When Arthur had heard that Lorena was in town, he was several things all at once: surprised, confused, shocked, worried, and, most of all, incredibly excited. When he had heard that she was staying in a motel, he was only one thing: on his way to get her. Since he was, at the time, not wearing very much (he had the tendency to go about his life, while in his apartment, in nothing but underwear), he threw on a pair of jeans and a t-shirt. And then he was out the door.
Being a superhero, it took him no time to get to where Lorena was. He followed the lines of doors until he came to the one with her number on it, and then he knocked. If it were Sub-Diego two years ago, he probably would have just walked in. But he didn't know if that would be unusual after not seeing each other for so long.