treasure, that has connections with the german lord henry the lion. we know that he visited constantinople and requested relics. but it's possible that may have had origins much older than that. ♪ >> should we get the bone out and have a look at it now? >> sitting in an elaborate gilt housing dating back to the 14th century, for the researchers the challenge will be how to remove the bone from its precious casing. ♪ and when they try to extract the bone from its mount, there's a problem. >> the mount does not come off of the bone. >> oh, you mean i can't actually take the bone out? >> no. >> and that means tom will struggle to reach the central part of the finger containing collagen, the most reliable material for carbon dating.