I shit you not, Rudeus' narration in the LN, he says he caught a familiar scent, and knew Roxy was near

Some skipped content. Yes the Dwarf was staring at Rudy's ass when they met. He was also not affected by succubus'. Elinalise tells Paul that she is Sylphies Grandmother. Geese has a cross mark on his boots so everyone knows where to step while they are following him. There is a side story of what Roxy has been doing for the month she was teleported. Rudy could actually smell Roxy. And she doesn't know it's him when she see him.