A trip to Rosie's favourite place - the swimming pool - ends in disaster when she decides she hates it. Emily begins to wonder if it's just that Rosie wanted to do something else. Simon goes off to take pictures of all the places they regularly visit to put together a booklet. Rosie types 'onetwoman', which Emily and Ben try to cross-reference with her iPad to figure out what it means. In the earlier timeline, Emily's academic nature and desire for answers is yielding much less success. At their first appointment with a genetics doctor, she finds him a like-minded soul who seems to view Rosie as a problem to be solved.

Rosie is incredibly excited. Grandad - aka Gandalf - is finally coming because there's going to be a birthday with lots of presents - albeit Ben's birthday presents.

A birthday meal out at a restaurant descends into chaos, but luckily Grandma has bought Rosie some presents to distract her. Everyone in the restaurant assumes it's Rosie's birthday, which in turn leads to yet more carnage. The only person unaffected by all this is Ben - she's just Rosie, after all.

In the earlier timeline, Simon and Emily are effectively leading separate lives, until Rosie's first laugh finally helps them move a little closer.