Harley Quinn (2000-2004) #22

It's the final chapter of Harley's trip to that big, bad place way, way below the surface. Harley's determined to escape her supernatural prison, but to do that, she's going to have to get past Highwater, the official doorman of the great beyond. But where brute force fails, perhaps the key to the prison lies in the key to the heart. Sound mushy? It ain’t!