Everyman 3318
Just got round to doing last weeks Everyman this morning and there are a couple of solns that I'm not completely clear on.
18dn is MAGPIE both from the letters and the fact it is referenced as a hoarder in 5ac, but why is it "Chatterbox, good in new game (6)"
Also, 12/13ac "Use the grapevine in part of castle, with one a threat, as it were? (4,2,3,2,3,6)" must be KEEP AN EAR TO THE GROUND and I see KEEP as part of castle and AN EAR TO THE as an anagram of one a threat but where does GROUND come from?
Thanks in advance!