Mission: Impossible (1966) : 7x16

Nicholas Varsi, an enemy assassin, has been captured but claims to be a defector who will reveal his mission to a government agency, the FIS...when he is guaranteed safe asylum. But the FIS may have been infiltrated by a deep-cover operative and Varsi may be selling fake information, so the IMF must verify if he really wants to defector. Jim and Willy break Varsi out and Jim claims to be an agent for Varsi's former government and demands to know why he is defecting. Varsi says nothing and shoots FIS agent Andrea (actually a guest IMF agent) with an empty gun. They let him and Andrea go - he'll turn Andrea back to the FIS if he's a true defector, but instead Varsi goes to a hotel to meet with his former superior, Colonel Kremmer, and the IMF must figure things out before Varsi and Andrea are both killed.