The Death of Henry Bouer is a backstory event. It saw the death of Prospero's director Henry Bouer, and the subsequent rise to power of The Custodian.
The Assassination Attempt on The Custodian was an attempt made on The Custodian's life in 1994 by agent Katie Downe after she learnt the truth about The Custodian's shady dealings.
The Advent of the Myths was an event that saw the introduction of long rumoured myths into San Andreas. X-Files IV Storymode follows CJ and Prospero as they attempt to deal with the crisis.