midnight
`` Right here . Now take hold of that end and we 'll soon have them up and be inside the building , '' answered Ham . While Ham and Carl were moving around under the boathouse , Shep and Snap were not idle . The doctor 's son , on awakening , had wanted to throw the flour paste out of the window at the midnight prowlers , but Snap thought of another plan . `` Come on below , and wait until they shove up the flooring , '' he whispered . The doctor 's son understood , and with caution , so as not to make any noise , the two chums came down out of the tiny loft , bringing with them the pail and the tin can of awful-smelling flour paste . It was absolutely dark below , but they could plainly hear Ham and Carl working on the loose boards of the floor near the river end of the boathouse .