The Stanton kids once again return to their vacation houseboat. When their old enemy, Mr. Powers, creates a vortex which sends him back in time, the children use their time machine to travel back to 1870, where Mr. Powers is a wanted bushranger who tries to hold them prisoner. In a race against time itself, they try to outwit him by destroying the vortex and leaving him stranded--this time with no possible way of escaping back to their time!