Previous appearances of blue kryptonite, such as Lara's ring and Dax-Ur's bracelet, have suggested that it must be in contact with a Kryptonian's skin before it will take away their powers. Yet the chunk Alia uses here removes both her and Clark's powers while laying on the floor, several feet away at any given time during the fight.
When John Corben meets Lois in the wreckage of the train, he asks her where she's been for three weeks. Confused, Lois picks up a tattered newspaper from the train to find out the date was Friday, September 25. However, the train crashed the previous night, so the date should have read Thursday, September 24.
When Alia is mortally wounded, Clark should have tried to get rid of the blue Kryptonite, as her returning superpowers would probably have healed her.
Lois: You might want to stick with your night job, detective. Graffiti's not exactly the Red-Blue Blur's style.
John Corben: You're right. It never used to be, back when the guy was happy pulling off a few modest saves. But then suddenly there was no red or blue. It was just the Blur. Now he feels he needs to leave his mark all over the city to--I don't know--to prove something.
Chloe: Dr. Hamilton.
Dr. Hamilton: If you would be so kind as to lower the 9mm Jericho 941. I prefer "Emil."
Clark: Isn't it time we moved beyond these mental trials?
Jor-El: Your determination is strong, Son, but just as your passion will be your greatest strength, so, too, will it be your greatest obstacle.
John Corben: Good find?
Lois: Look, on a scale of 1 to 10 of illegal things I've done in my life, this doesn't even hit the radar. Okay, that didn't exactly come out right.
Dr. Hamilton: I ran some scans at the time of the monorail crash and discovered two rips in the temporal aperture continuum.
Chloe: Okay, I've never actually said this before, but could you dumb that down just a little bit?
Chloe: I've given up so much for you, Clark. This is the only thing I've ever asked from you. Please? Please do this for me. Please save Jimmy.
Clark: I can't.
Chloe: That's good that you're embracing your Kryptonian side. There isn't really anything human left in you.
Lois: Who the hell are you, then?
John Corben: I'm a field reporter. I spent the last few years in Afghanistan. hopefully that gave me enough training to be your desk mate.
Lois: Don't bet on it.
UK: June 1, 2010 on E4/E4 HD
Sweden: June 11, 2010 on TV6
Turkey: January 16, 2011 on CNBC-e
Norway: February 6, 2011 on Max
Czech Republic: September 23, 2011 on TV Nova
Brian Austin Green and Terence Stamp are billed as special guest stars.
With this episode, Tom Welling receives co-executive producer status.
The new season credits feature Tom Welling, Allison Mack, Erica Durance, Cassidy Freeman, new show star Callum Blue, and Justin Hartley. Footage from several season 9 episodes is included.
In the comics, Metallo first appeared Action Comics #252 (May 1959). As with several Superman villains, there have been several different versions. Pre-Crisis, was crook John Corben rebuilt by an elderly scientist who used experimental techniques to put Corben's brain in a robot body powered by radiation. Corben killed the scientist and figured out he could use green kryptonite to power his body and pose a threat to Superman on that and many other occasions. Post-Crisis, John Corben was a small-time conman made into a cyborg by a xenophobic scientist who had acquired a bit of kryptonite and used it to power Corben's body. Corben fought Superman but his kryptonite was stolen by Lex Luthor. He has since found other power sources and acquired greater power by making a deal with the demonic Neron. In all of his incarnations, Metallo possesses superhuman strength, a robot body capable of absorbing damage, and occasionally the ability to extend and to some degree modify his limbs. He can also fire blasts of kryptonite radiation.