Do you know this book?

[PrincessButtercup]

I've been trying to recall the name of a book I read when I was 10 or 11 about a family who discover an ancient helmet in a walled up room.... I loved the book and would like to find it for my DS but cannot for the life of me remember anything else about it. Anyone?

Is it The Clifton House Mystery by Daniel Farson? I remember the TV series, (just).

Yes, that's it! Thanks Pascha. I only knew it as a book - didn't realise it was a book based on a TV series. I hope it is actually as decent a read as I remember it being. Just found it on Abe Books so I'll soon know....