What in heavens-above was that? Not everything seen on the night sky is understood. The Night Sky Live (NSL) project keeps its global array of continuously updating web cameras (CONCAMs) always watching the night sky. On the night of 2004 December 17, the fisheye CONCAM perched on top of an active volcano in Haleakala, Hawaii, saw something moving across the night sky that remains mysterious. The NSL team might have disregarded the above streak as unconfirmed, but the Mauna Kea CONCAM on the next Hawaiian island recorded the same thing. The NSL team might then have disregarded the streak as a satellite, but no record of it was found in the heavens-above.com site that usually documents bright satellite events. If you think you have a reasonable explanation for the streak, please contribute to the on-line discussion. Current candidates include a known satellite that was somehow missed by heavens-above, a recently launched rocket, and a passing space rock. Volunteers are solicited by the NSL project to help monitor the operability of each NSL CONCAM, including looking for interesting anomalies such as this. Disclosure: Robert Nemiroff collaborates on both the NSL and APOD projects.