When a diplomat's son is murdered, the Russian's want a Russian diplomatic security officer to shadow the 12th precinct on the case in Castle Season 8 Episode 11.

And that's how things kicked off this week on the ABC drama.

When he turns out to be a huge fan of Richard Castle and Nikki Heat, will he jeopardize the investigation...or Castle and Beckett's fake separation?

Use the video above to find out for yourself. Just click and follow its quick and easy prompts in order to check out all that just went down.

Enjoy the fun. Watch Castle online here at TV Fanatic.

C. Orlando was a TV Fanatic Staff Writer. Follow her on Twitter.