Here are the story beats in temporal order, kept fairly granular so you can see the arc of the session:

• The handler introduces Delta Green, the standing orders, and sets the mission in July 4th weekend, 2017.
• Each PC is introduced by vignette:
  • Sam Pine, an Olympic National Forest ranger in WA, writes a campfire ticket before leaving, gets paged, drives overnight to Fresno.
  • Kurtz, a UW computer science professor, leaves his daughter at his parents’ house after receiving a “night at the opera”-style activation text and heads to SeaTac.
  • Victor Sykes, a psychotherapist attached to a research group near U of I, gets a manila envelope dead-drop with ticket and instructions, arranges for a coworker to watch his one-eyed cat, Knox.
  • Shell, an astrophysicist in Anchorage, has rigged antennas to monitor anomalous radio signals; a special ping activates him and he flies to Fresno.
  • Chloe Cameroff, an FBI forensic pathologist, cancels a July 4th trip to her sons on Lopez Island, kayaks to the main island, then flies out.
• At Fresno airport, Sam (with the NPS vehicle and a DG envelope from a PO box) collects the others one by one; everyone clocks each other’s archetype (woodsman, nerd, shrink, astrophysicist, FBI doc) and previous op references (septic-tank burning, milk, amnesia).
• At a nondescript government-front office, a tired case officer briefs them:
  • Go to Ranchera Falls trailhead (Yosemite / Hetch Hetchy area).
  • A six-year-old, Brandon McGill of Topeka, Kansas, was found naked by a ranger yesterday.
  • Parents (whose son vanished in 1980 at age six) are en route; Brandon appears still six years old in 2017.
  • Objectives: locate the child, determine unnatural involvement, remove the unnatural element, and cover the incident.
• On the drive to Yosemite, the team uses phones for last-minute research before losing signal:
  • Shell finds a paper analyzing 40 years of Yosemite child disappearances, including patterns around the Hetch Hetchy / Ranchera Falls area.
  • That leads to a 1918 newspaper article about a child vanishing near Ranchera Dome and reappearing near the Devil’s Chair rock formation, with details about huckleberry bushes and miners finding a strange “female” corpse clutching a child.
  • Shell also digs up an essay about Ah-Ni folklore: cannibalistic proto-human giants driven underground by the local tribe, linked to huckleberry patches, liminal times of day, and children going missing.
• The team theorizes: underground giants, huckleberry “lures,” mushrooms as food or control mechanism, and possible time-slip / “time between times” phenomenon.
• As they climb into Yosemite, weather abruptly shifts from clear summer day to dark, oppressive storm clouds and changing air pressure; cell reception drops out.
• They arrive at the Ranchera Falls trailhead station—an old, two-story wood building with visitor center, ranger offices below, ranger bunks above—and note other ranger vehicles and an ATV.
• Outside, Sam gets some friendly ribbing from a young hiker (“pine pigs”) while the group decides how to split:
  • Chloe (FBI doc) and Victor (psychotherapist) will handle initial contact and interrogation of Brandon.
  • Sam, Shell, and Kurtz will gather environmental/local-lore intel, and potentially hike toward the Devil’s Chair and the find-spot.
• Inside, they meet Head Ranger Douglas Keena and ranger Tamika Gallegos. Douglas says Brandon’s been cleaned up as best as possible (no running water, just wipes), clothed in oversized spare clothes, and is resting upstairs.
• Chloe and Victor go upstairs, meet Brandon #1:
  • Six-year-old boy, brown hair, smudged, oversized clothes, asking for his parents and for Pringles.
  • Victor builds rapport, gets Brandon to describe what he remembers: visiting the park, trees, rocks, deer, huckleberries, then suddenly being “underground with really tall people” who “spoke without voices” and forced him to eat gray-blue mushrooms.
  • Brandon says he eventually woke up in bushes, near berries his mom had said were safe to eat.
• Chloe initiates a full field work-up on Brandon #1:
  • Nail scrapings, bowel and urine samples, hair root analysis, DNA comparison, potential aging-related markers, and an ultrasound/scan of his neck and head.
  • During hair root inspection, she finds a small subdermal lump at the base of his neck and a tiny tattoo of three squares resembling a stylized ram’s head above it.
  • Ultrasound reveals a solid cubic stone inside, not organic tissue.
  • When she lightly scrapes some tattoo pigment, it regrows itself almost instantly—tattoo fully restored—triggering a sanity loss.
• As Chloe runs tests (taking about an hour in-world), the “outside team” splits:
  • Kurtz wanders the trailhead displays looking for deeper info on indigenous histories.
  • Sam and Shell hurry up-trail toward the Devil’s Chair and the huckleberry zone before the storm breaks.
• Kurtz’s lore digging:
  • He finds generic signage about the valley’s “first peoples,” which a woman in an orange rain jacket (Dana) dismisses as false.
  • Dana claims descent from the “star people,” who traveled freely through time and space and now supposedly reside on a moon of Jupiter, awaiting stellar alignment to return.
  • She implies star people can go underground, seems eccentric/possibly tripping, and invites Kurtz to stargaze with her that night.
• Sam and Shell reach the Devil’s Chair area as birds fall silent and thunder rolls. They search for huckleberry patches and signs of disturbance:
  • Sam’s wilderness check reveals usual animal traffic and off-trail tourist damage, but nothing immediately unnatural.
  • Shell then hears a faint child’s voice from the opposite direction of Sam’s search and calls him over.
• Pushing through huckleberry bushes, they find a small “deer bed” clearing with a naked boy lying there—another six-year-old, matching Brandon’s description exactly.
  • The boy says his name is Brandon McGill, asks about his parents.
  • Shell wraps him in his coat; Sam gathers soil samples from the bed and looks for tracks.
  • Sam’s survival check shows something impossible: only Sam’s and Shell’s own footprints lead into the clearing; there is no trail indicating how Brandon arrived.
  • Just as they prepare to leave, Sam glimpses, at the edge of vision, a silhouette far too tall to be human among the trees—and then it’s gone, prompting more sanity checks.
• Over radio, Sam reports finding “another kid” and insists the rangers must not see this one. Shell, already stressed, partially blanks on the earlier kid when the second Brandon is in front of him, his mind refusing to reconcile two identical children.
• Meanwhile, Chloe’s test results on Brandon #1 come back:
  • DNA is a perfect match to the real Brandon’s father (whose DNA is on file from a past domestic abuse case).
  • Soil under Brandon’s fingernails dates to 1980; soil on his feet dates to 2017, confirming he disappeared then and reappeared now.
  • Stool sample shows evidence of substantial fungal ingestion consistent with mushrooms, but the species is unidentifiable at this point.
  • Hair root analysis shows subtle changes in keratin composition in the newest growth, suggesting environmental or dietary alteration.
• The storm intensifies, first heavy drops starting to fall. Sam and Shell rush back with Brandon #2, choosing to hide him from rangers by placing him in a separate upstairs bunk room, while Chloe and Victor repeat medical tests on him.
• Victor interviews Brandon #2:
  • The boy echoes the same memories—park visit, trees, deer, huckleberries—then stops short, reacting badly when asked about food.
  • When Chloe examines him, he goes into a panic, babbling “No, Oso dagawa, no mushrooms, no pigs, don’t want to go home,” then collapses unconscious.
  • Chloe finds a similar subdermal cube and tattoo on his neck, but the tattoo design differs slightly from Brandon #1’s.
• Chloe prepares to surgically remove the stone from Brandon #2’s neck, planning to biopsy surrounding tissue, check for chemical anomalies, and excise the tattoo skin. Shell has an anti-static/electronics bag ready to receive the crystal without direct contact.
• Downstairs, as the team regroups, a previously seen young hiker (the “pine pigs” jokester) comes up the stairs blank-faced and monotone, telling Sam and Kurtz, “Return the child. It’s ours. Return the child or perish.”
  • Sam and Kurtz physically block him; Kurtz tries to “talk cult” at him to buy time.
  • The man escalates, pushing forward. Sam restrains him and cuffs him.
  • As the storm peaks, a scream from outside interrupts them: guests and rangers see something hit a car; a car alarm blares, then abruptly dies after a crunch.
• Sam and the rangers step to the porch in the torrential rain, scanning with flashlights. They see a totaled car but no fallen branch.
  • As they sweep the tree line, both catch sight of a massive, seven-fingered hand reaching down from the roofline, grabbing Ranger Douglas Keena and yanking him up. His scream ends in a wet, crushing sound. Sanity checks ensue.
• Panicked, Sam drags Tamika and the basement guests toward the storm cellar, stripping Tamika’s sidearm from her before she shoots wildly. Kurtz warns everyone about a “bear attack,” steering them toward a bear-panic narrative while hustling civilians downstairs.
• Upstairs in Brandon #2’s room, Chloe successfully removes the stone cube with forceps:
  • It’s white, quartz-like, blood-coated, with a golden fleck at the center once cleaned.
  • The neck incision does not self-heal (unlike the tattoo pigment); the kid remains anesthetized.
  • Chloe preserves a tissue sample around the implant site to test for weird cellular changes.
• Kurtz, meanwhile, goes looking for something heavy to smash one of the crystals with. He doesn’t find a hammer (critical failure), but he does find a heavy book or paperweight.
  • A lightning flash reveals, outside the upstairs window, the huge, broad face of a giant proto-human: flattened nose, elongated skull, mouth full of two rows of human teeth. It hasn’t seen him yet; he fails to stealth, and the creature becomes aware of his presence.
• Downstairs, the storm escalates into full chaos: Sam and Shell hear a crash of glass and shouts from a ground-floor office.
  • A giant hand has punched through a window, groping inside. The “child” in that room—another altered form—attacks, clamping onto Sam’s leg with unnatural strength and trying to bite through his clothes.
  • Shell scrambles in, grabs bear spray from a shelf, and drenches the room and the attacking child with it. It has no effect.
  • In panic, Shell flicks a lighter, igniting the aerosolized bear spray; the room becomes an instant fireball.
• Amid flames and smoke, Sam fights to kick the child loose and finally resorts to his sidearm, shooting the kid multiple times until the body stops moving.
  • The second “child” that came through the broken window tries to clamber onto the desk but slips in the water and glass.
  • Shell sets off the fire sprinklers with a desk or object, dousing the flames while he and Sam unload bullets into the second child until it, too, goes limp.
• Upstairs, the giant outside Kurtz’s window lashes out with a pulse of blunt force, hurling him across the room and breaking bones; he barely stays conscious.
  • Chloe and Victor rush to stabilize him with medical care and pain meds; Chloe prepares to repeat the removal procedure for Brandon #1, knowing the crystals are the common factor.
• The giant’s arm, reaching in through a window, is severed in an explosion/attack (from the earlier bomb or accumulated damage). Its hand hangs inside the upstairs room, twitching, with rows of human teeth in its maw—the bear analogy solidified.
  • The group begins talking cover story: gaslight Tamika into believing it was just frenzied bears, not an underground giant; emphasize she smelled bear spray and saw mauling under storm stress.
• With the sprinklers running and structural damage mounting, the team decides on extraction:
  • Sam runs through the torrential rain to bring his NPS SUV to the front, under covering fire from Shell.
  • They load both anesthetized Brandons into the vehicle, along with as many Pringles as they can scavenge for later rapport.
• Kurtz stays behind to “clean up”:
  • He drags the hybrid child bodies out of immediate view.
  • He herds the basement civilians outside, yelling that the building is on fire and telling a story about bears driven mad by the storm.
  • In the utility area, he kicks open a gas/propane line, then lights a fire upstairs so that, once gas accumulates, the building will explosively burn, destroying evidence.
• Sam later returns for Kurtz; together they finalize the bear-attack cover: bears driven by the storm attacked the station, killed Ranger Douglas, and were repelled in a chaotic fight that ended with a gas explosion and fire.
  • Tamika is steered into remembering “only bears,” with bear spray smell and trauma used to anchor her altered memory.
• For the Brandons:
  • The team concludes neither child can be safely returned to the parents; the crystals and underground “giants” clearly link them to the incursion.
  • They plan a DG cover: DNA in a bloodied bag was misattributed; later confirm that the real Brandon died decades ago, and the “recovered child” was wrongly identified, with all physical evidence destroyed in the explosion.
  • The two surviving children will be taken into Delta Green custody—either fostered under deep cover or confined/observed long-term (Area 51-style).
• Back home, the epilogue focuses on Kurtz:
  • At his parents’ house, his young daughter plays while grandparents answer the door.
  • A chaplain and a police officer silently deliver the news that Kurtz died in the line of duty; his family collapses in grief, never knowing the true nature of his sacrifice.
• Mechanically, the handler notes that, by containing the giants, removing the crystals, destroying evidence, and keeping the incursion secret, the team achieved one of the “good outcomes,” regaining a small amount of Sanity despite losses during the op.