A riddle, huh?

[Lara stopped her own search, walking over and lifting her chemical light up to inspect the writing. It wasn't terribly complicated, not ultimately.]

Actually, this...is what I was looking for. I can take the letters I already know, and...

[She's quiet for several minutes, running her finger along each line of the carving Felicia's found...and after that she turns to look at the entrance.]

It can't be...