the unlikely love story started in swinging london in 1969 when our two heroes, john rendal and ace burken. >> so ace and i saw these two lions. a lioness and the cub that we subsequently called christian. and he was totally, totally irresistible. it was really a shock to see these beautiful creatures in such a tiny cage. >> we half wanted to rescue him from this situation, and we half thought it would be an adventure. >> anyone could see that he really loved us, we really loved him. we were part of his pride. >> eventually the lion became too big so john and ace took christian to africa and turned him over to a conservationist george adamson who would release him back into the wild. about a year later, john and ace went back to africa to look for christian and found that the magic was still there. >> he comes closer and closer and closer. and then you can just see that click of recognition. so we called him and that's when he took off. >> and he ran towards us with such excitement. the exuberance of it is what surprised everyone. the euphoria of that moment. in fact, we were all caught u