Mar-Vell was a Kree scientist who used to live on Earth where she worked with the United States Air Force in the framework of Project P.E.G.A.S.U.S., using the name Wendy Lawson. Together with Carol Danvers and Maria Rambeau, Mar-Vell worked on harnessing the energy of the Tesseract to create a Light-Speed Engine which according to her, would help end the Kree-Skrull War. Despite being a Kree herself, Mar-Vell intended to offer the technology to the Skrulls so they could relocate far from the Kree. However, Mar-Vell's betrayal was discovered by the Kree Empire, so the Supreme Intelligence sent the Starforce on Earth to eliminate her. While putting the engine on trial, Mar-Vell and Danvers were attacked by the Starforce, which caused them to crash, and Mar-Vell was eventually shot and killed by Yon-Rogg while trying to destroy the engine so the Kree could not control it.