The unidentified vessel closes in to attack, moving too quickly for "Enterprise" to lock phasers. The ship takes several hits from the attacking vessel. McCoy begins the operation on Sarek, who is receiving blood directly from Spock. Kirk orders Thelev brought to the bridge and questions him about himself and the attacking ship; Thelev is unresponsive. Kirk decides on a ruse, shutting down internal power to make "Enterprise" appear crippled. The attacker approaches, and "Enterprise" damages it with a surprise phaser attack. The disabled ship self-destructs, and Thelev reveals that both he and the ship were on suicide missions; he then collapses and dies from a delayed-action poison.