The twenty-second episode of the season, "Calling", initially had a different opening sequence involving Clark and Lana. In the original version, Clark and Lana were staying up late to watch a comet through Clark's telescope. Through the dialogue exchange between Clark and Lana, there was supposed to be a correlation between the arrival of the comet and Clark and Lana's relationship status. The comet also signified the arrival of Jor-El, Clark's biological father, and Clark's departure from Smallville. Unfortunately, the effect for the comet was expensive, and if they cut the comet they had to cut the dialogue because it would have made no sense if you could not see the comet. Instead, the scene was rewritten to be about Lana visiting Clark at midnight to celebrate his birthday.