Dinitia Smith’s fourth novel, “Honeymoon,’’ takes its inspiration from an actual event in the life of George Eliot, whom Smith calls “my literary heroine.’’ After the death of her longtime companion, George Henry Lewes, who was then 61, Eliot scandalized London by marrying John Cross, a man 20 years her junior.

“There was some gossip and laughter,’’ Smith said. “People said she looked like his mother, which she probably did.’’ Still, the pair’s honeymoon seemed to be going well until they got to Venice, where Cross attempted suicide by jumping off the hotel balcony. “The gondoliers rescued him,’’ Smith said; the couple moved back to England. Cross recovered from his breakdown, but Eliot died less than a year later.

“Very little was known about him or this event or why it happened,’’ Smith added. “The novel was really an exploration of this marriage, what could have been.’’

Fidelity to the truth was important to Smith, which was a challenge at times. “I didn’t want to make anything up,’’ she said. Eliot, she added, “was a 19th century woman who didn’t confide her deepest passions to her diaries or her letters, and thus that was where I wrote the novel, in that space.’’

The more she learned about Eliot, the more she found to admire. “I think that she was a marvelous person,’’ Smith said. “Not only was she a great, great writer, but she turns out to have been the kindest and most generous of people.’’

For Smith, writing her way into Eliot’s life was a familiar process: “I think there are two kinds of novelists: There are some who take from their own life, and others who like to travel, like me, into completely different worlds.’’

Smith will read 7 p.m. Tuesday at Harvard Book Store.

Kate Tuttle, a writer and editor, can be reached at kate.tuttle@gmail.com.