Boarding Gate

Paris[edit]
After discussing his plans for retiring by selling on the shares in his security company to his debtors with his partner, AndrÃ©, aging underworld entrepreneur Miles Rennberg is paid a surprise visit at his Paris office by aggressive underworld moll Sandra. Brazenly taunting him with her sexuality, she bluntly dissects their prior relationshipâa nightmarish web of masochism, money, manipulation and dependency, pimping her out to dangerous clients in order to gain both a business advantage and perverse personal thrills.
She outlines her newest ambition, since their estrangement, of raising the necessary capital to run a nightclub in Beijing. Miles makes no pretense of the fact that he is less interested in the proposal than the woman, and encourages her to visit him at his apartment.
Without making any promises, Sandra leaves for her job at an import business, run by a young married couple: Lester and Sue Wong.
Sandra's own import sideline, drug running, is facilitated by her close bond of loyalty with low-ranking employee Lisa. Acting as her driver and lookout, Lisa escorts Sandra to the site of a drug deal that quickly goes sour when her buyer is revealed to be a Narcotics officer. Suspicious after Sandra's cool response to his earlier queries about a missing container in a recent shipment, Lester follows Sandra to the deal and accosts Lisa as she waits in the car. He sends Lisa away on his motorcycle and takes her place in the car.
After Sandra emerges, Lester drives her away from the scene. Expressing disappointment in her deceit, he takes her back to her apartment where it becomes clear that the two are romantically involved. After their sexual encounter, Lester receives a call from his wife and leaves.
Sandra appears to relent and arranges to visit Miles at his apartment. Goading him with recollections of their misdeeds, she reveals a deep-seated bitterness; she recalls, in particular, an incident where a group of Japanese clients she was entertaining drugged and raped her, and Miles' arousal at hearing the episode recounted in front of his girlfriend. They both drink and end up on the balcony. Sandra undresses and tries to instigate a violent sexual game, apparently of the genre they used to practice, by pinning Miles to the floor of the balcony and choking him with his own belt. Miles warns her off and leads her back inside to show her a pair of handcuffs, which he intends to use on her later in the evening. She expresses reluctance which he nonchalantly waves aside. When she tries to leave, he locks the door and pockets the keys.
After he takes a business call, she playfully restrains him with the handcuffs, then brutally shoots him in the head.
She quickly retraces her steps through the house, destroying evidence of her presence, and makes a swift exit with Miles' keys. Lester picks her up, gives her a modest sum of cash and the name of a contact in Hong Kong who will arrange her new life, promising to join her soon. Lisa first drives her to a club to establish an alibi, where the oppressive atmosphere and the noise provoke an aggressively traumatic and regretful response to her act.[clarification needed]
Hong Kong[edit]
Hours behind Lisa, Sandra arrives in Hong Kong. She makes her way to the address of Lester's contact, who in turn sends her to a nondescript office somewhere else in the city. She is told that her contact is waiting for her in an adjacent room, but as soon as she enters the door is locked behind her. In the labyrinthine mess of the locked office she eventually discovers the bound and murdered body of Lisa in a chair facing the back wall.
A manifestly wealthy, middle-aged Western woman arrives at the office and orders the men to bring Sandra out, chastising them for Lisa's death. Eventually, one of the men in the office is sent in after Sandra. Having switched clothes and positions with the corpse of Lisa, she manages to ambush the henchman and escape onto the streets. Whilst crossing on a ferry she cries over her last souvenir of her relationship with Miles, his keys, before dropping them into the water. With little money and no recourse to her credit cards or passport, due to risk of capture and extradition for Miles' murder, Sandra resorts to repeatedly calling Lester.
She eventually manages to contact his wife, Sue, who maintains that Lester is unavailable but agrees to meet Sandra in a karaoke club. Sue is evasive and aggressive, revealing that whilst she knew of Sandra's affair with Lester, Sandra was not her husband's first infidelity and he never really planned to leave his wife to join her. The whole venture was an attempt to raise the investment capital for the Beijing club, an enterprise in which Sue was fully complicit. Whilst she attempts to take everything in, Sue spikes Sandra's drink with a sedative.
In a back room, Sandra threatens Sue with a gun and demands more information; Sue pleads her innocence until she manages to talk Sandra into succumbing to the drug's sedative effects. She leaves Sandra unconscious on the floor. Sandra wakes in the home of the wealthy Western woman whom she escaped in the offices earlier. The woman explains that she owes someone a favour and sets Sandra up with papers and well-paid employment in Shanghai.
Nonetheless, Sandra eschews the easy escape and tracks Lester down in a Hong Kong shopping mall. She follows him up the staircase with an unsheathed knife, but as she prepares to stab him she is interrupted by a group of women coming the other way. Lester enters an expensive restaurant, meets with Miles' business partner, AndrÃ©, and leaves with a sports bag full of cashâpossibly a payment for Miles' murder, which ensured that his shares did not pass to his unscrupulous creditors. Sandra follows Lester down to the doorway out to the car park, where he hesitates at the threshold as if aware of her presence. At the last moment, however, she finds herself unwilling to either kill or confront him. He drives away with the money.

Question: How she retraces her steps?