And then, perhaps worst of all, what happens if it finds gluten? Do I send the food back? I'd have to explain to my waiter—who I imagine is already annoyed—that I have this little device that has informed me their food which claims to be gluten-free is in fact, not. That I can't eat this dish now. That I'm so truly sorry. If the source of gluten is cross-contamination, I have no idea how they'd even go about preparing an option that I could safely eat, nor any idea if I'd feel comfortable eating there at all. I probably wouldn't, or at least wouldn't want to trouble anyone for another plate, which would leave me to smell other people's food and salivate in silence.