The Constitution, under command of Jules van Osterlich, was one of two Federation starships in 2364 to respond to reports of a deadly prion-based infection (which was, years later found to be engineered by Thallonian General Gerrid Thul). (TNG novels: Infection, Red Sector) In 2370, the Constitution was under the command of Captain Tiyo Soya. The Constitution and the USS Odyssey met with the USS Enterprise-D, after a Vulcan science vessel reported that the Enterprise was taken over by alien entities. (TNG novel: Possession)