Season 2
The first half of the second season deals with the team facing Thanos, as he competes with them to obtain the Infinity Stones, followed by a five-episode arc detailing the return of Ultron, who plans to exterminate the human race. The rest of the season details the arrival of the Squadron Supreme and their confrontation with the Avengers.
All Episodes
S2 E1: The Arsenal
S2 E2: Thanos Rising
S2 E3: Valhalla Can Wait
S2 E4: Ghosts of the Past
S2 E5: Beneath the Surface
S2 E6: Nighthawk
S2 E7: The Age of Tony Stark
S2 E8: Head to Head
S2 E9: The Dark Avengers
S2 E10: Back to the Learning Hall
S2 E11: Downgraded
S2 E12: Widow's Run
S2 E13: Thanos Triumphant
S2 E14: Crack in the System
S2 E15: Avengers Disassembled
S2 E16: Small Time Heroes
S2 E17: Secret Avengers
S2 E18: The Ultron Outbreak
S2 E19: The New Guy
S2 E20: Terminal Velocity
S2 E21: Spectrums
S2 E22: Midgard Crisis
S2 E23: Avengers' Last Stand
S2 E24: Avengers Underground
S2 E25: New Frontiers
S2 E26: Avengers World