do with its age? >> possibly. i mean, it looks -- it actually looks old, this wood. but it's just, you know, it looks aged. so far, so good. >> tom is satisfied with his sample. now they can head back to the lab to test for the first time this piece of the true cross. eight centuries before the waterford cross arrived in ireland, helena will continue her tour of the holy land, and with the backing of her son, the emperor constantine, she will transform the landscape. she builds churches on the site of christ's birth in bethlehem and one to commemorate his last moment on earth. >> constantine made it legal to practice christianity. helena gave christians places to practice christianity. before her arrival, there were no christian buildings in this land. christians met here on the mount of olives to commemorate jesus'