Baron wrote this as a prequel to Franco is Dying. It was revised and ready for publication - but never appeared. The novel came out for the first time in 2019, courtesy of Five Leaves, some forty years or more after it was written.

The War Baby is a compelling account of bravery and betrayal in the Spanish Civil War of the 1930s. Amid the last, faltering, steps to repulse General Franco's fascists, a young British Communist, Frank Brendan, heads to Barcelona on behalf of the Party. He becomes part of a hedonistic elite at the helm of what's left of Republican Spain before being sent to the battle front during the ill-fated Ebro offensive of 1938 - Republican Spain's last stand against the advancing falangists. He is a political commissar to the British troops among the International Brigades; his task is to 'expose the bad elements'.

Eventually, Brendan picks up a gun and joins an increasingly brutal and unequal battle alongside ill-equipped Volunteers. Few of the British Brigaders make it out alive; none are unscathed. The War Baby is a blistering account of the corrupting of the struggle against fascism. It is deeply critical of international Communism while compassionate and generous towards those who enrolled under that flag.