Abigail is found at the Sonar Collections Dock when playing as Michael De Santa after purchasing the dock by any of the three characters. Abigail speaks about her husband Frank Mathers and his death in a submarine accident. The insurance company believes that the submarine was tampered with and is unwilling to pay Abigail. She asks Michael if he would find the missing Submarine Parts in order to prove to the insurance company that there was no foul play. Abigail gives Michael a Dinghy with sonar in order to find the missing Submarine Parts. The parts can be found by any character after the mission has been started by Michael. Once the player find all the 30 submarine parts, the mission What Lies Beneath automatically begins.
- Talk with Abigail
- Find all the 30 Submarine Parts
The mission "Death at Sea" starts at 02:03
- After the mission is unlocked, news reports regarding Mathers' disappearance are heard on Weazel News and available online.