Castle returns on October 29, with a new episode “Probable Cause”, in which we could possibly find out who the murderer is! Check out the sneak peek below.

Episode Description: While investigating a shocking ritualistic murder, Beckett and her team uncover surprising evidence linking Castle to the killing. As the evidence against him mounts, loyalties are tested, and when surprising revelations come to light, Beckett begins to wonder how well she really knows her new lover and partner of four years.

The clip clearly shows Beckett, Ryan and Eposito showing up at Castle’s home with officers and a search warrant. What could they possibly have on Castle? Well it seems that the murder victim was given a piece of jewelry that can be traced to Castle! Beckett shows Castle a receipt for the necklace which cost the same amount of money he withdrew from the bank and there is a fingerprint! Before Castle can explain Beckett is called away by Ryan and whatever he finds leads to Castle’s arrest! What could Ryan have found to lead to Castle’s arrest? Does Beckett really believe Castle is capable of murder? What will this do to the newly formed relationship between Castle and Beckett? So many questions! Hopefully all of these questions will be answered on October 29.