The enemy ship approached without suspecting it was travelling into a trap.
The Nautilus lit up both forward torpedo banks, unloading a total of six proton warheads at short range. The enemy had no time to react. The torpedoes all hit and detonated and in an instant the front of the ship simply ceased to exist. It collapsed into itself in a cloud of bubbles and debris.
Nemo was on the bridge surveying the results. "One down," he said to himself quietly.