Heat the oven to 400°F, with a rack in the upper third. Scrub and debeard the mussels.
In a small bowl, stir together the bread crumbs, garlic, parsley, thyme, and cayenne. Season with salt and pepper and stir in the remaining
Bake until the crumbs are golden, about 10 minutes. Serve the mussels with lemon wedges and eat them straightaway.