Chess queen trap Scandinavian / Center Counter defence, plus lesson, themes, tactics!

A chess queen trap in the Scandinavian / Center Counter defence. 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Bd2 Nc6 6.Bb5 Bd7 7.Nd5 Nb4. The dubious move is 5. …Nc6?? instead of c6. A simple but devastating queen trap!