The detectives investigate a murderer who poisons hospital victims with cyanide. They suspect a nurse whose profile is typical, but when they discover more murders away from the hospital they have to widen their search.

Anita Gillette, Anne O'Sullivan, Beth Bailey, Brian McCormick, Charles Dumas, Daniel Jenkins, Erik Frandsen, Gary Galone, J. Smith-Cameron, Jerry Orbach, Jesse L. Martin, Joanna Scorcia, Kate Hampton, Laura Scribner, Les McDonough, Lynda Baquero, Madison Arnold, Marc Damon Johnson, Margaret Goodman, Mark Gordan, Michael Cullen, Myra Lucretia Taylor, Ray Demattis, Robert Levine, Robert Stoeckle, Robin Miles, Samantha Lucier, Spencer Chandler, Stephanie Roth Haberle, Susan Bruce, Travis Walters