El-Adrel IV was the uninhabited fourth planet in the El Adrel system. The planet was close to territory claimed by The Children of Tama. It was the homeworld of a non-sentient species. It was in the same sector as Kanda IV, Malindi VII, Razna V, and Shantil III.
In 2368, a Tamarian deep space cruiser entered orbit of El-Adrel IV and began sending a signal to the Federation. The USS Enterprise-D arrived three weeks later and attempted to establish communications, but was unable to understand the Tamarians' language.
Captain Dathon of the Tamarians then transported himself and Captain Jean-Luc Picard of the Enterprise-D to the surface of El-Adrel IV, knowing that there was a hostile energy creature there. Dathon hoped that the shared danger would bring Picard to understand him, and he succeeded though at the cost of his own life. The Tamarian vessel had established a scattering field in the planet's ionosphere to prevent the Enterprise-D from interfering, as well as disabling (but not damaging) a shuttlecraft sent to land on the planet. The Enterprise took down the scattering field in time to rescue Picard from the creature. (TNG: "Darmok")