Final Fantasy IV - Interlude - Final Fantasy IV - Interlude - is a bonus feature side - game bundled in " " with " Final Fantasy IV " and " " . It can be played and completed independently of either game from the main menu , and covers events that link the two games . Gameplay . " Interlude " uses the same gameplay system as the PlayStation Portable release of " Final Fantasy IV " , which is based on the Game Boy Advance release . Characters have the same abilities , spell lists , sprites and equipment pool as in the original game , and enemy encounters are similar including dropped items . The game is linear , with airship flight being controlled by NPCs and the player unable to return to most areas after flying to a new location . Filling the game ' s bestiary unlocks several entries in the art gallery that is shared between the three games . Story . Approximately one year after the party defeated Zeromus , Cecil dreams of Rydia entering a Crystal Chamber , where a voice says " Finally , it has a new form . " As the voice is about to reveal itself , Cecil ' s wife Rosa wakes him — they are headed for Damcyan to celebrate the reconstruction of the castle . Meanwhile in the Feymarch , Rydia prepares to leave to attend the ceremony after speaking with the Eidolon Asura . At the celebration , Cecil meets with Palom , Porom , Yang , an Epopt , the Elder of Mysidia , and Edward ' s secretary in training . During the celebration a guard arrives to tell Yang that some monks were attacked by monsters on Mt . Hobs . Yang leaves to investigate , Rosa and Cecil accompanying him . They find the monks and heal them , aiding them in fighting the Dad Bomb , and explain they were on their way to Damcyan because in Fabul , Yang ' s wife Sheila is about to go into labor with their child . The group returns to Fabul and witness Sheila give birth to Ursula , Yang appointing Cecil as her godfather . They prepare to return to Damcyan when Cid arrives in the " Falcon " with Palom , Porom , and Luca . Monsters are pouring out of the Sealed Cave , overwhelming the dwarves . Rosa and Cecil prepare to accompany them to investigate , but Rosa falls ill and remains behind to rest . Cecil accompanies the four to the " Falcon " and they depart to the Underworld . Meanwhile in Eblan , Edge departs the castle . In the Underworld , Cecil , Cid , Palom , and Porom , enter the Sealed Cave . In the Crystal Chamber they find Rydia collapsed in front of the Dark Crystal . She awakens and has no memory of how she came to the Crystal Chamber , but tells the group she must go to the Tower of Babil . The group leaves the cave , Rydia telling the group that something is calling her , and the Tower of Babil begins to glow ominously . Concerned about Rydia and the tower , the group flies the " Falcon " there to investigate . Meanwhile , Edge makes his way through the Eblan Cave that connects to the tower , worried about the glow as well and suspecting someone has been to the tower . At the tower in the Underworld , Cecil and the group climb it , encountering elemental monsters who , when defeated , impart the power of Eidolons to Rydia . As they pass the cannon control room Rydia enters it and three monsters emerge to stop Cecil and the others from getting to Rydia . The three guards merge , and Edge arrives to lend a hand in defeating it . After the battle , they enter the control room to find Rydia is gone . Continuing climbing the tower they find Rydia , who turns out to be an imposter . The woman attacks the party , summoning her Eidolons one by one when they are defeated . When she summons Bahamut , the real Rydia arrives and brings Bahamut to his senses , allowing the group to fight the imposter . Though she is weakened , the woman vanishes before the party destroys her . As they wonder who she is , a scene shows her in the Crystal Chamber at the top of the tower . She announces to an unknown entity that " the Eidolon system " is complete , before vanishing . Back on earth , in Cecil ' s bed chamber in Baron Castle , Rosa lies in bed and Cecil asks if she is alright . Cecil goes to the throne room to the other party members and reveals Rosa is pregnant . Everyone is overjoyed and tells Cecil he should start coming up with names . Meanwhile , on Mt . Ordeals , Kain is training in solitude when he hears a voice call out to him .