'Castle' sneak peek: Castle defends Hayley to an MI6 agent

The Castle fandom might be speculating about Hayley's intentions, but the crime-solver himself doesn't seem to have many doubts, even when prodded by an MI6 agent.

It all goes down Monday in an all-new episode called "Backstabber."

In a sneak peek of the episode, Hayley Shipton (Toks Olagundoye) looks on from the panic room as the queen's secret serviceman insists that Hayley was not framed after all. Richard Castle (Nathan Fillion) defends Hayley, but the agent claims that Hayley is the type who would let Castle -- or Alexis -- die to save herself. Can Hayley be trusted? You be the judge in the clip above.

Castle airs Monday at 10 p.m. ET|9 p.m. CT on ABC.

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