Father Marcus was a priest and friend of Joel Dexter. In October 2018, Joel Dexter asked Father Marcus to oversee the wedding ceremony of himself and Cleo McQueen. Cleo's family overheard Joel and Father Marcus talking, and Father Marcus ended up telling them about the wedding. On the day of the wedding, Cleo suffered a heart attack at the altar due to a bullimia relapse. Father Marcus later told Joel that he had told Pete Buchanan - unaware of his connection to Cleo - about the wedding ceremony.
In January 2019, Father Marcus learned of Cleo and Joel's separation and visited Joel in an attempt to convince him to rejoin the priesthood, accompanying Joel to the soup kitchen for the homeless. In March 2019, Myra McQueen spoke to Father Marcus about potentially holding her wedding to Sally St. Claire at The Dog in the Pond as opposed to a church.