The Infiltration into Pym Technologies Headquarters was an attempt by Scott Lang to prevent Darren Cross from selling the Yellowjacket Suit to HYDRA.
Hank Pym broke Scott Lang out from his cell inside a San Francisco Police Department police station by smuggling him the Ant-Man Suit and guiding him out.
The following day, Pym and his daughter Hope van Dyne started training Lang through a series of trials, preparing him to steal the Yellowjacket Suit from Darren Cross at Pym Technologies.
Lang infiltrated the New Avengers Facility to steal a device created by Pym that was intramural to the mission and defeated Falcon in the process.
Just when it seemed like their caper was going smoothly, Pym got an unexpected visit from Cross. Lang and van Dyne concealed themselves, as the former commanded his ants to conceal evidence of their caper.
After Cross left Pym's house, he called van Dyne, announcing his intention to increase security at Pym Tech. Realising their plan had hit a snag, Lang brought in his associates, Luis, Dave and Kurt in on the caper.