• in S06E02, Castle helps investigating the case because he has only a day to live and that way helps so well solving the case he becomes again an assistant to Beckett's team, praised by the federal agents even if he should not be involved ; smart way to have him work again with Kate I think, and good job on the script.
  • at some point in the future, captain "Iron" Gates leaves the 12th precinct or is killed and Beckett is offered the role of captain there, accepts and goes back to NYC, reuniting with Esposito and Ryan and of course Castle.