“The first support here at the lip is holding up the graffiti wall, while the inner one is supporting the foundation wall for the vault of Peter’s tomb. The space beyond the inner truss is the interior of the tomb. If you want to crawl in there, you’ll be able to see a notched niche in the base of the red wall if you look to the right. That’s where the bones the pope claimed were Saint Peter’s were found, the ones they have a level up in the Plexiglas boxes.”

“I think I’ll pass,” Sana said. The thought of crawling on her stomach through the low tunnel into Peter’s tomb made her queasy and awakened the claustrophobic fears she’d been trying to suppress. It took all of her self-control to keep from fleeing back out to the area under the glass deck and then back up through the opening to the gallery above.

“Let me show you something else,” Shawn said as he crawled into the tunnel and then rolled over on his back. He pointed up at the ceiling using his flashlight and tapped the ceiling between the two trusses. “The ossuary will be up here, if it wasn’t discovered by accident when either the red wall or the graffiti wall was erected. Now, hand me the drill and the goggles. I’m going to probe a bit and see if I can make contact with stone.”

Sana concentrated on Shawn’s commands to avoid thinking about the entire mass of Saint Peter’s Basilica pressing down on top of her. When Shawn was ready to begin, she said: “If you don’t mind, I’m going to move out to the more open area under the glass deck. I’m having a bit of trouble breathing here.”

“Suit yourself,” Shawn said, distractedly. He was thrilled to be back to field archaeology. After he put the pail next to his body, he tried the drill. Its whine seemed particularly loud in the confined space. Satisfied with the drill’s performance, he put the tip of the bit up against the ceiling. The bit cut through the hardpan like a knife through butter. Within seconds it buried its four-inch-long shaft up to the hilt. Dry dirt rained down mostly on his chest, although some went into the bucket. Mildly disappointed not to hit stone on the first attempt, he pulled the drill bit out and moved six inches to the left and tried again.