Will a USO Bring Hynek & Quinn Together in the 'Project Blue Book' Finale? (VIDEO)

Damian Holbrook

Apparently the sky's not the limit when it comes to alien life on the UFO-hunting drama, which draws from another real-life declassified case for its second-season finale.

This time, instead of flying saucers, scientist Allen Hynek and Air Force Captain Michael Quinn (Aidan Gillen and Michael Malarkey, above) investigate a possible unidentified submerged object on Project Blue Book. The USO was spotted during a joint military exercise on the border of Russian waters and then reported by a U.S. battleship.

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Find out how the scripted drama is blending reality with fiction.

Despite resistance from the ship's commanding officer, Hynek and Quinn refuse to back down (they find themselves adrift — literally!), "even if it means risking their lives," previews showrunner David O’Leary.

That desire to discover the truth, he adds, brings the unlikely duo "closer together than they've ever been…[but] it will also be the force that [possibly] separates them."

Project Blue BookSeason 2 Finale, Tuesday, March 24, 10/9c, History