The seventh and longest story in Halo : Evolutions, 'The Mona Lisa' is set in the Soell System during the period between Halo 1 and Halo 2. The narrative follows the crew of the UNSC Red Horse who are on a recon mission to investigate the fate of the UNSC Mona Lisa, which has mysteriously come to rest near the destroyed Alpha Halo Installation. After they discover an escape pod with a survivor in it Sergeant Lopez and her team of marines board the Mona Lisa. It is only after she arrives on the ship that Lopez realises that all of her team had been exposed to the survivor. So begins a parasitic nightmare and desperate struggle for survival.
