Captain America could’ve been erased in “Marvel’s Agents of S.H.I.E.L.D.” Season 7, episode 2. The ABC drama currently has the team in the past to keep the timeline intact, and that means brushing with important parts of SHIELD’s past—such as the super soldier serum.

“Marvel’s Agents of S.H.I.E.L.D.” featured Freddie Malick (Darren Barnet) transporting a liquid for Hydra. After realizing the female agent (Nora Zehetner) has been to Germany six times in the last year, Jemma Simmons (Elizabeth Henstridge) sees a drop of bright green serum on the Hydra agent’s shoe. She runs some clever tests and realizes that this is a prototype for the super soldier serum.

“It was synthesized by a German scientist named Abraham Erskine,” Simmons says. “And first used by a man named Johann Schmitt.”

“The Red Skull,” Daisy Johnson/Quake (Chloe Bennet) realizes.

“Freddie Malick is about to deliver the key ingredient used to create the super soldier serum,” the biochemist confirms.

Daisy immediately wants to stop the serum from being transported. Stopping the Red Skull would save thousands, but Phil Coulson (Clark Gregg) reminds her that they aren’t supposed to change the timeline. The Chronicoms are in 1931 trying to stop Hydra because it will prevent SHIELD from being formed, and then they’ll be able to take over the Earth.

No one mentions that no Red Skull also means no Captain America. Erskine, played by Stanley Tucci in "Captain America: The First Avenger," was the scientist who made the super soldier serum that was injected into Steve Rogers.

Ultimately, saving the super soldier serum would massively change the future, and—as Coulson has pointed out—that could allow someone even more evil to step up and gain power.

Luckily, despite a close call, the serum and Malick were left untouched. Hydra (and, technically, Captain America) is saved—at least for now.

Expect the agents to have more secondhand connections to the Marvel Cinematic Universe’s early days. Enver Gjokaj is set to guest star as Agent Daniel Sousa, a character from “Agent Carter.” Viewers last saw him working alongside Cap’s longtime love/S.H.I.E.L.D. founder/goddess Peggy Carter (Hayley Atwell).

“Marvel’s Agents of S.H.I.E.L.D.” Season 7 airs Wednesdays at 10 p.m. EDT on ABC.

SHIELD captain america Captain America's origin story plays a part in "Agents of S.H.I.E.L.D." Season 7, episode 2. Left: Chris Evans as Captain America. Right: Clark Gregg as Phil Coulson. Photo: Marvel Studios; ABC/Mitch Haaseth