Tantalus field

From the Memory Alpha Information Directorate, a side project of Memory Alpha.

The tantalus field was a 23rd century device found aboard the ISS Enterprise, which could be used to monitor and eliminate enemies from existence with the touch of a button.

Captain James T. Kirk owed his success against a number of enemies to the tantalus field, and the unknown alien scientist whose lab he plundered for it. The field was apparently a secret from everyone except Marlena Moreau, and to others it seemed that Kirk's enemies had a tendency to "simply disappear." The field was used by Moreau to save the Kirk from the mirror universe when he was trapped in this universe. (MM)