The eyes of the Doctor widen for two specific reasons: how the bloody hell a box filled by twenty cat pins can be found inside her bedroom specifically and how one of them can look like her cat for Six hadn’t meet her cat before? Even when he trying to think about a situation when such a thing happening...nothing coming inside his mind. Six never give him such a box (he always meeting him outside the box, the inside one being very specific)

Unless...

[SMS] I’m coming. It’s seems I will need to call a old friend for get back it.