Morbius and Simon Stroud are back from Helleyes' dimension and being attacked by vampires beneath Mason Mansion. Morbs is incensed because even though he's a living vampire he doesn't believe in the supernatural kind. That's unfortunate because they're trying to murder him, believing or not! Stroud, however, even after getting a chance to escape can't bring himself to abandon Morbius, and they battle on. I love a good enemies- to- allies trope.
We segue to Martine still being interrogated at police headquarters. She's trying to convince them that her lover Morbius is not responsible for his actions- which again raises the issue- is he responsible for his bloodlust when the crazy afflicts him? Meanwhile the other vampire that the police have captured gets free and proceeds to make short work of the detective. Aww...
"'Free to drink!"
"For a moment there is nothing but silence in the small, grey room... then comes a slurping, wet and hungry licking sound as the fallen inspector's life is drawn from the veins in his neck... and when his chest has ceased to rise, the blazing yellow eyes of the vampire turn on a horrified Martine!"
Back to Morbius. The bloodlust is on him and and even as he tries to warn Stroud away, he loses control and attacks! The assault carries them into a celebration full of... vampires! A whole party of bloodsuckers. But why do they bleed? Morbs slakes his thirst on one of them while Stroud is nearly overwhelmed, but thankfully Morbius saves the day. The mystery remains though- who is creating all these vampires? I'm still wondering why they bleed.
At any rate, Stroud is now a reluctant ally of Morbs, and they return to police HQ- to find it in chaos. The vampire has been rampaging and Morbius fears the worst. He kills her but imagine his shock when he finds Martine...
"And only now do I truly understand your lusts, my darling!"
Yes, Martine has been turned. A vamp.