Lex Luthor follows the trail of the black spheres to Arkham Asylum in Action 897 (March 2011), by Cornell and Woods. Hate that cover, aside from the Lex logo.
The Joker finds Lex Luthor is even less fun to play with than Batman, but that doesn’t stop him from trying. The Joker is in possession of the black sphere, and is able to touch it and interact with it in ways no one else can.
So the Joker does give Luthor some insight into the sphere, but nothing Luthor finds useful. As with his conversation with Death, Luthor only hears what he wants to hear.
When Luthor is out of the room, the Lois-bot pushes Spalding into the sphere, then blames this on the Joker when Lex comes back.
The issues ends, like the others, with a tease of the next guest-villain. Larfleeze is in Las Vegas, and on the hunt for Luthor.