Detective Jim Ellison is a police officer with the Cascade police department, but he is no ordinary policeman.

Jim Ellison is a Sentinel

After returning from an ill-fated mission to Peru, then army ranger, Jim discovered that his senses had become strangely acute. Normal everyday sounds were at times painfully loud and his senses of taste and sight were spiralling out of control.

On a chance meeting with anthropologist, Blair Sandburg, Jim finds out that abilities such as his have been recorded since time began, especially in tribal cultures.

Each tribe would have a Sentinel who guarded the village, able to detect danger and act as protector.

Jim allows Blair to become his 'guide' and help him understand his unusual gift, thereby using it in his job as police officer and 'protector' of his 'tribe', the citizens of Cascade.

 

Ellison, played by actor Richard Burgi, is at first a cold and troubled man, on the verge of mental breakdown. But, with the help of Sandburg, his new 'guide' and soon to be closest friend, he learns that what he has been given is a gift and not a curse.