Holy Saturday was an appropriately solemn day at the National Shrine of the Immaculate Conception, as the faithful prayed in side chapels, said their confessions and prepared for Easter rites that were only hours away.

Down in the crypt, Kristin Kazyak paced before a life-sized color photograph of the Shroud of Turin. For hours, she answered familiar questions about the 14-foot sheet and how its lightly scorched fibers offer a negative photographic image that contains 3-D information. She discussed the brutal details of Roman executions, from roofing spikes hammered into wrists and feet to lashes tipped with spiked metal balls. She talked about the pros and cons of carbon dating.

"What we see here is not beautiful," said Kazyak, who managed this Washington, D.C., exhibit. "We can see every wound Christ suffered for us. ... It's bloody. It's shows trauma and torture. It hurts to look at it. We can see the ugliness of sin and human evil."

Finally, someone asked a new question: Isn't there another cloth similar to the shroud?

Kazyak located two photographs of bloody patterns on cloth. The first -- from the shroud -- showed its famous herringbone weave. But the second was of a more humble piece of linen, woven in a taffeta pattern.

This second blood pattern is from the Sudarium Christi (Face Cloth of Christ), which has been venerated at the Cathedral of Oviedo in northern Spain since the sixth or seventh century. Researchers claim they have found documentary evidence tracing it to first-century Jerusalem.

"When you take a photograph of the blood on the back of the head on the shroud and you superimpose it over a photograph of the blood on the back of the head on the Oviedo cloth, they match," explained Kazyak. "They are exactly the same size and shape."

Each cloth has matching blood and serum stains from the mouth, nose, beard and hair of someone who appears to have been beaten, crowned with thorns and killed by asphyxiation, which is consistent with crucifixion. The blood on both cloths is type AB. The length of the broken noses on both is 8 centimeters. This is hard to explain if, as carbon-14 tests indicated, the shroud was created between 1260 and 1390 A.D.

What is the Sudarium? The Gospel of John says that when Peter and John reached the tomb of Jesus, they found a shroud and "the napkin, which had been on his head, not lying with the linen clothes but rolled up in a place by itself."

This makes sense, according to a 1998 paper published by a trio of Spanish scholars. Under Hebrew law, it was the custom to cover a corpse's face when it became bloody or disfigured. This bloody, unclean cloth would be removed as the body was placed in a proper shroud, and then left in the tomb. Researchers who believe both cloths are genuine theorize that this is why the Oviedo cloth does not contain a scorched image, like the shroud.

There's more. According to work by Avinoam Danin, a Jewish botanist at the Hebrew University in Jerusalem, the Turin Shroud contains pollens from a thistle plant, the Gundelia tournefortii, which grows only in the Middle East. This would be a likely plant from which to create a cap of thorns. It blooms in the spring -- near Easter -- and the imprint of a flower from the plant was found near the shroud's head image.

Pollens from this species are on the Sudarium Christi, as well. It appears that both cloths contain myrrh and aloes from burial rites.

Obviously, research must continue on these mysterious pieces of linen, said Barrie Schwortz, chief photographer for the 1978 Shroud of Turin Research Project. The shroud will be on display between Aug. 12 and Oct. 22, but the status of new tests is unclear. Thus, new attention may be focused on the Sudarium Christi.

"If these blood patterns came from contact with the same face, then that means those Medieval carbon dates for the shroud are off by six or seven centuries and maybe more," said Schwortz. "At that point, we have a whole new set of questions we have to ask."