Plot Summary:Peggy Desmond, the daughter of an Irish magistrate, loves Captain Neil Dacey, but is pursued by Terence O'Malley, the nephew of Squire O'Malley, a wealthy landowner. Although the squire offers to pay off the Desmonds' debts if Peggy were to marry Terence, Peggy refuses. After Neil invokes the name of Rory O'More, the \"Will o' the Wisp,\" a legendary Irish Robin Hood, Peggy dresses up as a highwayman and robs Squire O'Malley, then gives the purse to one of the squire's poor tenants. As the local law officer, Neil is assigned to capture the bandit, but is robbed himself by his clever incognito sweetheart. When the squire turns up dead, Neil, whose gun is found next to the corpse, is arrested and jailed. To free her love, Peggy disguises herself once more as a highwayman and forces Terence to confess to the murder at gunpoint. Once released, Neil deduces that Peggy is the bandit and makes good on her promise to marry the man who succeeded in unmasking the \"Will o' of the Wisp.\"
