Matt Murdock, Jessica Jones, Luke Cage and Danny Rand investigate criminals and fight injustice, unaware their paths are about to cross.

As a new conspiracy takes shape, Matt finds old habits are hard to break, Jessica gets in over her head, Luke tracks a lead, and Danny meets his match.

Elektra's loyalties are questioned, Colleen clashes with an old acquaintance, and Luke proves he knows how to take a hit.

Matt, Jessica and Luke embark on a desperate search. Colleen and Claire debate heroism. Elektra tries to recruit an all-important ally.

As New York edges closer to disaster, Elektra sees what's beyond the wall, and the Defenders make a last-ditch effort to save the city.