Plant ID. What is this intruder?

Canary27

On the left an eryngium (Miss Marple), on the right an achillea (Cloth of Gold?). Yes, I know they are probably planted too close together, but what compounds the problem is the unexpected appearance of another plant (in the middle of the two) which I don't recognise. It is obviously vigorous and the leaves are not unattractive. If it's a weed I'll try to eradicate it, but if it is something more interesting I'll try and move it. Can anyone help

Loxley

Looks a bit like hedge woundwort. Do the leaves have a strong pungent smell?

Canary27

Slightly pungent, but not very strong. The leaves have a velvety / hairy texture, a bit like some mints. Here's another one that is trying to muscle in on the Geum.

Silver surfer

I agree..Stachys sylvatica..common name Hedge woundwort.

https://www.google.com/search?q=Stachys+sylvatica,&rlz=1C1CHBF_enGB785GB785&source=lnms&tbm=isch&sa=X&ved=2ahUKEwj9qP7k6uroAhUEXRUIHd4bCkcQ_AUoAXoECBUQAw&biw=1920&bih=937

Dovefromabove

I agree too 

Canary27

Thank-you everyone for your identification. Just googled it, and apparently it is a wild plant with magenta flowers very popular with bees - so I may try to move some of it to a wilder spot in the garden. I'll have to be careful though because it appears to be very invasive: "Once the seed is dispersed, the plant also spreads vigorously using its underground rhizomes (stems)."

Palustris

It really is a thug. We spent years trying just to keep it under control in our last garden. I hate the smell of it too.