Martha Clifford, Leopold Bloom's "typist" and erotic pen pal, is an unseen character in Ulysses whose existence nevertheless penetrates deeply into the mental fabric of the novel. She is a secret shared between Bloom and the reader, yet Joyce, Bloom, and Martha herself all effectively conspire both to hint at and conceal her identity. This essay discusses the identity of Martha Clifford and raises questions whose answers have both interpretive and biographical implications. After reviewing extant theories on Martha, I add a new suggestion: that she is a foreigner and non-native English speaker. My support comes primarily from a close reading of her letter and other textual evidence. I also draw connections to Giacomo Joyce and the mystery woman (or women) at its center. Extending the biographical criticism forward, I consider Joyce's attempted affair with Marthe Fleischmann as a case of life imitating art. Ultimately, Martha Clifford's foreignness contributes to Bloom's fantasies of the exotic, particularly through linguistic eroticism but also to the novel's larger examination of nationalism and identity.