Oh Bella! When her ex-husband Martin shows up at the birthday party of their godson Tom with his new love Catrin Reichelt, a spontaneous showdown ends up with Bella accidentally hitting a ball on his head. Martin is taken to the hospital unconscious. Diagnosis: amnesia. The past years of his life have been erased from his memory. Catrin is not amused in the least by the fact that he also can not remember her. Martin finds himself thrown right back into his marriage with Bella and is surprised by the independent, self-determined life that she - so suddenly – appears to be leading. Out of a sense of responsibility and guilt, Bella helps Martin and together they out on a search for his lost memories.
In the process, both discover that – besides their shared past and their godson Tom - there is much more that unites them. Nevertheless, in the interest of reason they decide to continue living their present lives. If Martin is really that happy with Catrin – then why not stay with her? He'll just fall in love with her again. Bella now goes out with charming, poetic carpenter Nick, who also dances the tango like no other. But soon Martin realizes that when it comes to Bella, reason can not offer a permanent solution.