What do you do when a Russian diplomat’s son is murdered in New York?

Call Castle and Beckett, of course.

Now, let’s recap:

We open on a young man, Grigory Mishkin, who ventures through an abandoned (read: creepy) warehouse and has his throat slit by a mystery assailant.

Enter Castle.

Although he might be a little distracted by shopping for the perfect baby shower gift for Ryan, and the struggle is real. Alexis and Martha make the right call when they say baby Kevlar might not be the best choice.

That baby lightsaber DOES sounds amazing, though.

Castle turns up at the precinct to greet Ryan with the perfect gift basket that Alexis concocted and talk about the new case. As the main suspects and the victim, himself, are diplomat’s children, they fall under diplomatic immunity. A Russian Security consultant is brought in to assist them with the case.

Enter Vasiliy Zhirov. I want him to get his own spin-off.

The gang follow up with a “diplo-brat” who uses his immunity to get away with everything and who they believe may have killed Grigory. When the NYPD’s investigation gets halted by his immunity, Vasiliy takes Castle for coffee and threatens the young diplo-brat with “Russian Justice”. His lips start flipping very quickly.

This, then, leads the gang to discover a Russian Defector who is currently in witness protection under the pseudonym Frank Thomas, who was involved with Grigory’s mother — a former soviet spy.

Beckett sends Vasiliy off with Castle on a site-seeing mission — after all, he is a massive Castle fan and loves Nikki Heat so much he came up with a concept for the next book — and Vasiliy finds Frank Thomas and kidnaps him.

Stepmother turns up and informs Beckett she works for Russian intelligence.

Before Vasiliy has a chance to torture Frank, Castle deduces that he was creating fake IDs for a party at the Russian Consulate, so someone could pose as a cater waiter. 

The gang turn up to the consulate as Vasiliy’s plus-ones, and Beckett thwarts an assassination attempt.

And I start having flashbacks to the Season 3 finale, “Knockout”. What an episode.

Anyway, the leader of the consulate is saved, but Sergei — a diplomat and the murder victim’s father — is shot in the chest.

Ryan finds footage, after they discover it was a rare Russian sniper rifle that shot him, and finds out that it was Sergei’s ex- — and presumed dead — wife.

They track Anya down, and she says she tried to kill Sergei because he killed Grigory because he was not Sergei’s son.

However, Sergei can’t be arrested under diplomatic immunity. He goes back to Russia, but Vasiliy subtly hints that he is being deposed to the coldest part of Russia to pay for his crimes.

Now that’s Russian justice.

What did you think of this week’s double installment of Castle, folks?