Now, here goes the question. Our hidden character this week is not a person, although it is related to one, since we are looking for a relic. Here you have the hints:
1) It is organic
2) Two French abbeys claimed to have IT (yes, only one of this stuff, if any, can exist)
3) It's existence, although unquestionable according to Christianism, poses a great theological problem
4) The main canonical source about its very existence is precisely one of the Gospels.
Which medieval relic are we talking about?
P.S.: Núria Sallés was spectacularly brilliant answering our last quiz, congratulations!!! Try this one... if you dare ;)