Hi ID,
The return would always be to the nominated landing runway. Several reasons: the departure runway may have been contaminated by debris left by the returning aircraft, if the returning aircraft blocks the landing runway it is easier to set up single runway operations from the departure runway, and the departure runway may not be available for landing due cranes etc. The landing runway would already have the ILS and lights selected and would usually be the most suitable option. (In practice we would try and make both runways available to an aircraft in dire emergency).
As for "slotting" you in, as an emergency you have absolute priority and you could make a visual circuit to land, or a radar circuit of whatever length you specified. Everything else would be broken off, sent around or switched to the other runway if possible. We practice for all these eventualities on the simulator.