Money Heist season 4 ends in a precarious place for the Professor (Álvaro Morte) and the gang, and leaves plenty of unanswered questions for season 5. While fans might have assumed that season 4 would wrap up the Bank of Spain heist (similar to how the first two seasons covered the Royal Mint heist), the gang are still holed up by the time the credits roll on the finale - and they don't seem to be in any hurry to leave.

Much of Money Heist season 4 was spent dealing with the fallout of season 3's cliffhanger ending, in which Nairobi (Alba Flores) was shot by a sniper. The gang was able to nurse her back to health, just in time for her to be murdered in cold blood by the bank's chief of security, Gandía (José Manuel Poga). Meanwhile, on the outside, the Professor orchestrated a daring jailbreak for Lisbon (Itziar Ituño) that ended with the police unwittingly allowing her to join her friends via a military helicopter drop.

Related: Money Heist Character Guide: Every Robber's Real Name & Backstory

It's been a dizzying series of triumphs and tragedies that has currently left the Professor and the gang on top of the scoreboard after exposing the crimes of Alicia Sierra (Najwa Nimri) and other high-ranking officials to the world. There's still the matter of escaping the Bank of Spain with 90 tons of gold and somehow evading capture to be dealt with, however. Can they pull it off? Here are the biggest unanswered questions that Money Heist season 5 needs to answer.

What Does Alicia Sierra Plan To Do With The Professor?

Alicia Sierra interrogating someone in Money Heist.

Just after celebrating the victory of Lisbon rejoining the group, the Professor had his lair discovered by Alicia Sierra. Once the police inspector in charge of negotiations for the Bank of Spain heist, Alicia is now a woman on the run with a warrant out for her arrest over the torture of Rio, the attempted murder of Nairobi, and the unlawful holding of Lisbon. Given that the Professor is responsible for exposing her crimes it might be assumed that she intends to either kill him out of revenge, or bring him to the police in the hope of reducing her own sentence. But a smart woman like Alicia probably has something better planned than murder or surrender, and she may actually have decided it's in her best interest to join the heist - whether the Professor likes it or not.

How Will The Gang Escape The Bank Of Spain?

La Casa de Papel Money Heist season 4

The biggest Money Heist mystery that has been deliberately left unanswered so far: how are a gang of Interpol's most-wanted criminals planning to get themselves out of the Bank of Spain, along with 90 tons of gold, when the building is completely surrounded by police and military forces? They haven't been digging a tunnel like last time, and probably wouldn't try the same trick twice anyway. The only clue we have is that the gold is absolutely crucial to their escape.

Could the Professor be planning to enlist more outside help, maybe offering some of the gold as payment? Perhaps the gold is even a complete misdirect; after all, the real goal of the heist was to free Rio, and even after dropping millions of euros over Madrid the gang still has plenty of their near-billion euro haul from the last heist left over. Will the gold be sacrificed to help them escape, or will they somehow get away with both their lives and the loot?

Related: Money Heist Theory: Sierra Will Join The Gang In Season 5

Who Will Take Over Police Negotiations?

Colonel Tamayo looking concerned in Money Heist

With Alicia gone, there's an empty chair at the negotiating table in the police tent. The negotiator plays a pivotal role in Money Heist's dance - first with Raquel Murillo a.k.a. Lisbon's complicated cat-and-mouse chase with the Professor in seasons 1 and 2, and then with Alicia's merciless and rule-breaking tactics in seasons 3 and 4. Colonel Tamayo (Fernando Cayo) could potentially step in, but his short fuse is a poor fit for negotiating and he's still reeling from the shock of the helicopter trick. Ángel (Fernando Soto) was smart enough to identify "Salva" as the Professor in seasons 1 and 2, but he's more of a follower than a leader. Money Heist season 5 may well bring in a brand new character - untouched by the scandals of Rio's torture and Lisbon's arrest - to take over negotiations for the police.

Will There Be Justice For Nairobi?

Nairobi lying in the sand in Money Heist

Easily the most shocking and controversial moment of Money Heist season 4 was the sudden death of Nairobi, a fan-favorite character whose focus on the job has been a grounding element in a show full of hotheads, loose cannons and big egos. Nairobi had a son that had been taken away from her, and was planning to have a second child and start a new life for herself after the heist, making her death all the more tragic. The villain responsible is Gandía, the nigh-unstoppable former black ops soldier turned security chief, who is currently held captive by the gang. They will face a moral quandary in Money Heist season 5: with Gandía at their mercy, killing him would go against their code of ethics and the Professor's rules. But with the police unlikely to hold Gandía accountable for killing a robber in a hostage situation, how else can the gang ensure that justice is served for Nairobi's murder?

What Are Marseille and Bogotá's Real Names?

Money Heist Marseille and Bogota

The Professor told the gang to use city names from the start so that they wouldn't know each other's real identities... but that plan has since fallen apart. The names of every member of the original crew have now been revealed, and the only two characters whose names we don't know are the new additions for the Bank of Spain heist: Marseilles (Luka Peros) and Bogotá (Hovik Keuchkerian). They haven't received as much character development as their colleagues (for much of Money Heist seasons 3 and 4, Marseille's main role was to ferry around two old cell phones that connected the Professor to the police), but that can be expected to change in season 5. As we learn more about them, perhaps we'll learn their real names as well.

What Happened To Sofia?

Money Heist Sofia The Ferret

And finally, the most important unanswered question of them all: what happened to Sofia, Marseille's pet ferret? Sofia's role was to act as a decoy, using Rio's GPS tracker to make it look like the gang were escaping into the sewers. The last time we saw her, Sofia was facing down a squad of officers in the sewers, even wearing a tiny red jumpsuit to identify her as a member of the gang. Presumably she was taken into police custody and is now being treated as evidence, but it's unlikely that an animal lover like Marseille would be willing to leave his pet in the hands of the enemy. Hopefully in Money Heist season 5 we'll see a small-scale version of Lisbon's jailbreak executed for Sofia.

More: What To Expect From Money Heist Season 5