TELEOS-1

Set between the events of Halo 4 and Halo 5: Guardians… Halo: Nightfall tells the dramatic story of legendary man hunter and Naval Intelligence Officer Jameson Locke and his team as they are caught in a horrific biological attack while investigating terrorist activity on the distant colony world of Sedra. As they unravel a plot that draws them to an ancient, hellish artifact, they will be forced to fight for their survival, question everything and ultimately choose between their loyalty and their lives.

After a construction project begins digging in their neighbourhood, best friends Tuck, Munch and Alex inexplicably begin to receive strange, encoded messages on their cell phones. Convinced something bigger is going on, they go to their parents and the authorities. The three embark on a secret adventure to crack the code and follow it to its source, and discover a mysterious being from another world who desperately needs their help. The journey that follows will change all their lives forever.

Three astronomers accidentally intercept what they believe to be a signal from a distant alien civilization, but the truth is even more incredible than any of them could have imagined.

Ba'al travels back in time and prevents the Stargate program from being started. SG-1 must somehow restore history.