Dr. Alexander Kline, a biological scientist, views his work as evil, and to prove it, he plans to unleash a deadly germ that would kill thousands. Three dead cows lead McGarrett on a desperate chase to track down the toxin, involving a friendly telephone operator and top Washington agents.
| Name | Type | Role | |
|---|---|---|---|
| Anthony Lawrence | Writer | ||
| Karl Swenson | Guest Star | ||
| H.M. Wynant | Guest Star | ||
| Ed Flanders | Guest Star | ||
| Ken Drake | Guest Star | ||
| Dana Elcar | Guest Star | ||
| Bernard Ching | Guest Star | ||
| Lynne Ellen Hollinger | Guest Star | ||
| Fred Titcomb | Guest Star | ||
| Yankee Chang | Guest Star | ||
| Loretta Swit | Guest Star | ||
| Elizabeth Smith | Guest Star | ||
| Marvin Chomsky | Director | ||
| Leonard Freeman | Director |