The Turtles' failure to stop the signal to the Triceraton armada leads to an all out war between the Kraang, Triceratons, and Earth.
A recurring dream helps Castle and Beckett discern clues about his two month disappearance but their search has deadly consequences.
Ben faces off against both Zs'Skayr and the terrifying Lord Transyl.
Complications ensue when Castle and Beckett finally try to take Senator Bracken down after finding evidence connecting him to a young woman's murder.
His relationship with Beckett strained, Castle teams up with Detective Ethan Slaughter from the city's gang unit. But Slaughter's kind of police work could put Castle in real danger.
The team has their toughest case ever when a sniper on a killing spree in New York City has no apparent motive. The case is especially hard on Beckett as she tries to hide her progressive PTSD moments which are surfacing.moreless
A wealthy museum patron is a suspect when a valuable sculpture is stolen. Castle and Beckett investigate the theft with the help of an insurance investigator who sets her sights on Castle.
The Squaddies face the Dark Surfer in a series of one-on-one confrontations with the fate of reality hanging in the balance.
As Beckett fights for her life, Castle attempts to find the person responsible for the shooting. Meanwhile back at the precinct, Ryan and Esposito try to adapt to the new captain in charge.moreless