Let’s say it’s leap year, let’s say Sherlock hasn’t returned yet from the dead, let’s say Tom and Molly haven’t gotten engaged yet. Let’s say encouraged by her friends Molly decides she should do it. Let’s say Tom’s supposed to pick her up at her work. Let’s say Molly’s nervous and speaks too quickly when she thinks he’s walking in. Let’s say the man who she just asked to marry her steps out from the shadow - is Sherlock (you never expected that) and he says ‘Yes’.
Let’s say someone writes it.