 In The Mark of Athena, Hazel learns her former boyfriend, Sammy Valdez, was Leo's great-grandfather.Until he falls in love with Calypso in The House of Hades, Leo flirts with almost every girl he meets in order to cover up his insecurities about never finding love.In The Blood of Olympus, Leo sacrifices himself to annihilate Gaia and dies in the process, but is brought back to life using the Physician's Cure and returns for Calypso on her island, Ogygia.