Amy E. Gilbert and Joshua Samuels Atkins are to be married Sunday in San Francisco. Rabbi Bruce Greenbaum is to officiate in the Penthouse of the Fairmont Hotel.

Ms. Gilbert, 31, is keeping her name. She is studying for a Ph.D. in molecular medicine at King’s College in London. She graduated from Middlebury.

She is a daughter of Kathy Kearns of San Francisco and the late Nathan Gilbert, who lived in San Mateo, Calif. Her mother retired as a program manager for Meals on Wheels in Santa Cruz, Calif. Her father was a lawyer in San Mateo.

Mr. Atkins, 34, is the lead game designer for Fable III, a video game series produced by Lionhead Studios in Guildford, England. He graduated from the University of California, Santa Cruz.

He is a son of Cynthia K. Samuels and Dr. Richard N. Atkins of Washington. His mother owns Cobblestone Associates, an online Internet consultancy in Washington. His father, a psychiatrist, retired as the chief executive of the National Prostate Cancer Coalition in Washington.

The couple met in November 2003, as members of a Seattle Works volunteer team, while cleaning a homeless shelter.

“We both had lived in Santa Cruz, so we had this immediate connection,” Mr. Atkins said. “She was really cute, and we ended up talking for about 10 hours that day — it was one of the best days of my life.”

They managed to clean one of the two shower stalls in the shelter. Ms. Gilbert had volunteered first, and then Mr. Atkins quickly volunteered to help her.

“I was glad he raised his hand to help me because we had talked briefly before, and I got to like him right away,” Ms. Gilbert said. “While we were cleaning we talked about so many things — Santa Cruz, music, traveling, we just never really stopped talking.”