I have some ideas on where the next leg could be. The one major city in Europe never visited by an Amazing Race is Madrid and another is Seville.
The major destinations from Mallorca are Germany, the mainland in Spain and the United Kingdom. Air Berlin holds the majority of destinations at the airport, including Alicante, Amsterdam, Barcelona, Frankfurt, Hamburg, Madrid, Valencia, Seville and Murcia. Air Europa offers flights to Granada, Malaga, Paris-Orly and Rome-Fiumicino, and Iberworld flies to Aberdeen. Easyjet and Ryanair, two very popular low-cost airline companies offer a number of destinations from the airport as well. Other prominent airline carriers departing from Palma de Mallorca Airport include Lufthansa, Thomas Cook Airlines, Thomson Airways, Norwegian Air Shuttle, Bmibaby, Jet2 and Vueling.
When I look at today's departures (yesterday's would be similar), I found only 2 nonstop to Seville, although you can connect in Madrid to get there. These nonstops were at 1515 this afternoon and at 2215 tonight.
To Madrid there are a wealth of flights: