It Was Inevitable
It Was Inevitable is an achievement in Halo: The Master Chief Collection. It is unlocked by beating the 16,000 point par score on Two Betrayals. The achievement is worth 10 gamerpoints. Though it can theoretically be unlocked on any difficulty, more points are awarded in campaign scoring when playing on higher difficulties.
The name of the achievement is another Firefly reference. In the episode "Serenity", Wash (Alan Tudyk) is playing with two dinosaur models, during which the Tyrannosaurus turns on the Stegosaurus, who then exclaims, "Curse your sudden but inevitable betrayal!"