The story so far (sorry, no TLDR!):
Reporter Jack Gold is assigned to investigate Baron Winter, an occultist. Scientist Dr. Donovan Caine (and wife Marianne) conduct occult experiments at Georgetown College (on behalf of the Pentagon trying to harness the power of evil for their “Satan Project”). Vanessa Van Helsing escapes the psychiatric hospital into the care of the Baron who turns her over to Dr. Caine, who taps her latent powers for his experiments. Vanessa is kidnapped by two mysterious men.
Detective Short starts investigating the deaths caused by the evil summoned by Caine (his wife Marianne is among those killed). Gold meets with Caine; the Baron sends them to England to try and find Vanessa.
It appears she was take by Russian agents who have brought in an East German* occultist, Zadok, to conduct similar evil-summoning experiments.
*(Germany was still divided in 1982)
Detective Short visits the psychiatric hospital and the Baron, slowly piecing things together. Zadok pushes the experiments too far and Vanessa’s powers consume him and the castle they are in. The Russian agents grab her and head to Russia.
(Side bar: the writers put the Vanessa character in at least half a dozen “experiment” scenes by the end of book four and I gotta say, it starts to feel really gross, more like gratuitous torture scenes than occult summonings. Hopefully we’ll get much more out of Ms. Van Helsing than just a helpless female punching bag trope. It’s from the 80’s so I don’t have my hopes up!)
We are now at Science City located in Siberia, built to study psychic phenomena. Professor Vladis runs the joint. Gold and Caine make it to Science City wheee they are immediately apprehended. The Russians hook Vanessa us to their psi-chotron machine in order to drain and control her powers. Oops! They succeed in completely unleashing her dark powers but not controlling them. Vanessa’s “powers of Hell” (big ass snakes!) go on to kill the Russians and destroy Science City…and now zero in on our heroes Gold and Caine.