There is some nomenclature collision here.
There is the Magic Pie which has a controller
integrated into the hub.
There is also the BAC-281 Magic Controller which is the
nifty silver one. That controller replaced the
earlier ones where you had to get a different
controller if you wanted 24, 36 or 48V.
If Henning has the BAC-281, his motor should
have one long cord coming out that ends in one
white hall sensor plug, and three colored wires.
If he has the Magic Pie wheel, then it has two plugs
as shown in the photo below, one for +/- Battery,
and one for the various inputs like throttle, brake,
and switches.