Mystery Climber

Today's the day ....................... to identify?

It's not often that we find something growing in the garden that we have absolutely no idea what it is - but we found this today and I have to say that it's a bit of a mystery.

It is a climber and I have a vague memory of getting something in Tesco (as you do) which I thought was a passion flower.  Nothing happened last year, so I assumed that it was a goner and vowed never to buy any plants from Tesco again (as you do).  But here it was today, sort of in the same place, but climbing over other plants in a different direction - and not looking anything like a passion flower.

I'm hoping that one of you experts out there can throw some light on things?  It would be nice to know what it is .......................