The Lives of Others

When an injury leaves him house-bound and bored, Castle becomes convinced that he has witnessed a murder — but with no body, no evidence and no other witnesses, Beckett begins to wonder if his writer's imagination is getting the better of him. While Castle enlists Alexis to help in his off-the-books investigation, Beckett is left to take the case of a murdered IRS agent on her own. Castle's murder case is ultimately revealed to be an elaborate surprise birthday present staged by Beckett, which inspires her to take a closer look at the evidence in her own case.