Other books written by O'Brien include "An Béal Bocht"—translated from the Irish as "The Poor Mouth"—(a parody of Tomás Ó Criomhthain's autobiography "An t-Oileánach"—in English "The Islander"), and "The Hard Life" (a fictional autobiography meant to be his "misterpiece"). As noted above he may, between 1946 and 1952, been one of the writers to use the pseudonym Stephen Blakesley to write up to eight books of the protracted series of "penny dreadful" Sexton Blake novels and stories, and he may have written yet more fiction under a wide array of pseudonyms.