I am at once fascinated with and repelled by the technological advances in medicine. Let me clarify that. I'm fascinated with non-invasive technological advances and repelled by the invasive ones. I spent my childhood in terror of rectal thermometers. When I recently took my daughter (the six-year-old, three-foot tall antichrist) to the doctor, the thermometer was a Star Trek doohickey that was stuck into her ear canal for a nanosecond and provided a digital readout.

A bout of pneumonia I experienced a few years ago was resolved with medication and without the hospitalization it would have required twenty or so years ago. But a prostate gland examination still requires a … well, prostate gland examination. And a bloodd test requires extraction with a hypodermic needle. My last doctor visit ended with my being informed that we'd be doing blood work next month. My thought was, "No we're not." That was two years ago. I'm waiting for some sort of gadget that Gene Roddenberry dreamed up years ago, where I lay down on a table or stand in a booth for twenty seconds and get diagnosed and cured all at once. Which brings us to OBSESSED. And MRIs.

MRIs are those wonderful diagnostic machines that are the bane of claustrophobics. They make the patient feel as if they're being stuffed down a clothes dryer loaded with athletic shoes. I believe I've seen advertisements for open MRIs (back to Star Trek and that diagnostic table) but I'm also fairly certain that they have somewhat limited utility. OBSESSED, however, is concerned with the mothership of all MRIs.

OBSESSED is the fourth in G.H. Ehpron's fine series concerning psychologist Dr. Peter Zak, who balances his career with his resolving but residual grief over the murder of his wife and the ups and downs of his relationship with Annie Squires. OBSESSED finds Zak attempting to help a co-worker who is being stalked by an unknown individual. The co-worker is Dr. Emily Ryan, who Zak is supervising during her postdoctorate period while she works part-time at Pearce Psychiatric Institute. The stalker's anonymous acts continue to escalate, and Zak is becoming increasingly concerned about where, and when, the violence will end.

Ryan, meanwhile, is splitting her time and attention between Pearce and University Medical Imaging Center, which is performing revolutionary research in the diagnosis and treatment of Lewy body dementia. The driving force behind this research is Dr. Jim Shands and a new, extremely powerful MRI unit. When Zak is given the opportunity to witness the powerful MRI in action, he jumps at the chance. He also finds that the trail of Ryan's stalker seems to lead back to UMIC.

Zak is further drawn back to UMIC when Squires's uncle begins to exhibit signs of dementia and is considered potentially to be afflicted with Lewy body dementia, a provisional diagnosis that makes him a candidate for MRI study. When one of UMIC's associate physicians is killed in a suspicious accident, Zak is slowly drawn into a self-driven investigation of UMIC and Shands. Zak discovers that the Lewy body dementia patients who have been evaluated at UMIC seem to be experiencing premature morbidity and that Ryan's still-unknown stalker may be linked to it.

Ephron (a pseudonym for a writing duo consisting of a journalist and a forensic psychologist) continues to do an excellent job of melding medical and psychological issues with entertaining mystery plots while simultaneously developing Zak's life and personality. The moral and ethical issues that Zak encounters in his professional and personal life are real and true to life --- the occasional difficulties in his relationship with Squires ring especially true, as does his almost involuntary attraction to Ryan in OBSESSED --- and bode well for future novels from Ephron. Zak is complex enough as a character that readers of this series will look forward to his return, and Ephron's, for some time to come.