Captain America is tasked with getting hold of the Mind Stone, which is placed securely in Loki’s scepter, as seen originally in 2012’s The Avengers.
There’s a very famous moment that takes place in the pages of Captain America: Steve Rogers #1, as written by Nick Spencer.
So, Cap is locked in an elevator with a bunch of Hydra agents and it looks suspiciously like that amazing elevator scene from Captain America: The Winter Soldier.
This leads Steve Rogers to a packed elevator, full of characters such as Brock Rumlow, aka Crossbones, and Jasper Sitwell, individuals we come to know as agents of Hydra in Captain America: The Winter Soldier.