One of the pockets of distorted time, running fast, slow or backwards, scattered around a Romulan warbird and the Enterprise-D frozen at the instant of an apparent battle in the episode Timescape.
Temporal fragments are small regions in which time passes at a different rate from the space around them. They are met in The Next Generation episode Timescape in 2369, when Picard, Troi, Data and La Forge return from a conference by runabout.
The first signs are odd: Troi sees her companions freeze in mid-sentence, a bowl of fruit rots in moments, an engine nacelle runs out of fuel after apparently weeks of use, and Picard's fingernails grow long when his hand enters a fragment. Ahead they find the Enterprise and a Romulan warbird locked motionless, with a warp core breach beginning aboard the starship.
Using emitters that shield them in their own time frame, the four go aboard. The cause proves to be aliens from another continuum who mistook the warbird's artificial quantum singularity for a natural one and laid their young in it. Picard and Data avert the explosion.