As soon as you hear that Snape was found in the Shrieking Shack with Voldemort, you didn't waste time finding him. You were one of the professors in the Hogwarts -- the only one that believes that Severus is not in alliance with The Dark Lord.

Even as the Headmaster after Dumbledore's demise, things might have changed a bit in Hogwarts, but you know deep inside those scowls and stern demeanour, lay the vulnerable Severus Snape.

When you arrive at the Shrieking Shack, Voldemort already left the place, along with his blasted pet -- Nagini.

All you found was Severus laying against the windowsill of the Shrieking Shack, his neck oozing a huge amount of blood. His eyes were empty, he didn't scream or yell for help.