Who Killed Wade Walker?

When millionaire Wade Walker's plane explodes mid-air, Burke confronts Walker's business partner, secretary (whom Tim has an eye for), and the four women in his life (a model and beauty pageant queen, a society horse breeder, a starchy, sex-obsessed nurse, and a nightclub singer), one of whom Walker may have proposed to just before he died. All of Burke's theories go up in smoke when it is discovered that Walker died of an overdose of morphine before the plane blew up.