Ilirra Deel was a Betazoid female who worked for Starfleet Intelligence in the 24th century. Deel was considered an extremely gifted telepath, even for a Betazoid. In the mid 2380s she worked as SI's liaison to Sarina Douglas. Douglas considered Deel to be a friend. Deel trained Douglas to be receptive to telepathic communication from her, and taught her how to create mental messages that Deel could read.