Castle (Seasons 1–8)

Castle (2009) is ABC's crime-comedy series you can watch online on iFILM. Best-selling mystery novelist Richard Castle (Nathan Fillion) talks his way into the NYPD, shadowing homicide detective Kate Beckett (Stana Katic) under the guise of research. The case files are real. The chemistry between the two is even more so.

Eight seasons, 173 episodes, and one of TV's most drawn-out will-they-won't-they arcs — the show wrapped in 2016 after becoming a reliable ratings hit for ABC. Creator Andrew Marlowe built each episode around a clever crime hook, then used it to peel back layers of Beckett's past and Castle's surprisingly sincere heart. Fillion's comedic timing and Katic's straight-faced cool keep the formula from going stale.

Stream all seasons of Castle online on iFILM — procedural crime with wit, warmth, and a slow-burn romance that earns its payoff.