Su Ryeon spends a pleasant time with her kids, but Seok Kyung is not happy how Su Ryeon and Seok Hoon are overly generous to Ro Na. The newlywed couple, Dan Tae and Seo Jin, go through a tough time adjusting to prison life.
The moment Seo Jin is released from prison, she visits her daughter, Eun Byeol, but Eun Byeol avoids her. Meanwhile, on the day of the performance test, students are getting ready at the examination hall for Seoul University of Music.
Su Ryeon stops Jun Ki from shooting Dan Tae at the restaurant. Jun Ki finally meets Su Ryeon and tells her the truth behind Dan Tae's real identity. To take his revenge, Jun Ki meets everyone around Dan Tae.
Since Yoon Hee is searching around to find the truth behind Dan Tae's crime, Dan Tae decides to get rid of her. Meanwhile, Ro Na and Seok Hoon try to help Eun Byeol as Bun Hong was getting more and more obsessive over her.
Seo Jin becomes the director at the Cheong A Arts Center. Eun Byeol wakes up at the hospital, and despite the good news of her getting into Seoul National University, she becomes frantic. Ma Ri vows to help Su Ryeon takedown Joo Dan Tae.
As Dan Tae believes his plan to be foolproof, he asks Seo Jin for even more money. However, when things don't go the way he planned, he takes a big risk in an attempt to make up for his losses.
To help find Seok Kyung, Seok Hoon fools Dan Tae into thinking that he wants to take over his father's business and starts digging for clues. Meanwhile, Ro Na shines at the Cheong Ah Arts Residence Audition.
Joo Dan Tae and Cheon Seo Jin celebrate together for having their plan go through, blaming Logan's death on Su Ryeon. However, they each know that soon the other will be after their throat.
Su Ryeon and Logan get Dan Tae and Seo Jin right where they want them, fighting against each other. As they throw evidence that can destroy them at their faces, Seo Jin and Dan Tae fight each other to survive..
Joo Dan Tae tries to escape on a boat as a fugitive. However, when he wakes up, he finds himself confined and as Baek Jun Ki. Meanwhile, evidence that Seo Jin may be the murderer in Oh Yoon Hee's death surfaces.
Seo Jin survives and recovers in the hospital. However, Su Ryeon believes her mental state is all just an act. Meanwhile, loan sharks wait by her hospital bedside, keeping watch as Eun Byeol tries to fight them off.
Su Ryeon defeats Dan Tae and sends him plummeting to his death. However, he takes down Hera Palace, blowing it up as he planned. Meanwhile, Yoon Chul wakes up and discovers that Seo Jin's dementia is all a sham.
Su Ryeon falls over the cliff and doesn't resurface. The rescuers search to no avail. Meanwhile, Seo Jin stands trial for the murder of Oh Yoon Hee and the attempted murder of Su Ryeon.
In this special episode, the actors of The Penthouse talk about all the various memories they made during the long 540 days of filming. As they share how they felt on their first day, the script reading day, they also talk about their most memorable scene and to whom they are most thankful. Also, stay tuned to check out the touching messages they give to their own characters in the series.
