You return to your hometown after receiving a letter from an old friend, uncovering a gruesome truth — one of the locals is no longer human. Talk with the locals and find out who is human and who isn't. At nightfall, spy on suspects while avoiding the police, watch news about worldwide worm plagues, check yourself in the mirror just in case, and sleep to move on to the next day. Notice patterns, strange words, and distinct behavior. Connect the dots and reach your own conclusions.