It was an admirable scheme, beautifully simple, and could scarcely fail to achieve complete success, but for the fact that Captain Harrison had contrived to obtain full particulars of it, and therefore knew exactly how to frustrate the plan.  His plot was as simple as that of the slavers: he would proceed in the _Psyche_ to the scene of operations, and when the decoy schooner made her appearance she would be permitted to go on her way unmolested, while a boat expedition would be dispatched up the river to the town of Olomba, where the vessels actually engaged in shipping the two thousand blacks would be captured _flagrante delicto_.