BEIRUT - In Umm Mohamed's suitcase there is a neatly folded black abaya and niqab, while to the side of her seat she has piled a pair of shoes and socks. "All black," she smiled, holding up her handbag, also black. "I got it to make the trip, just to be on the safe side."

The 70-year-old woman firmly holds the bus fare that will take her from Beirut's Charles Helou bus station to Raqqa, the de facto capital in Syria of the Islamic State of Iraq and the Levant (ISIL).

Before arriving to the first checkpoint manned by ISIL fighters, somewhere between Damascus and Palmyra, the bus driver will allow Umm Mohamed, the only female passenger on the bus, time to change out of her leopard-print hijab and into the black garb, then he will ask her to move to the back of the bus.

"I'm going to see my son and his family," said the elderly woman. "I want to go back to my own house; Syria might be finished but it's still my home."

She is not alone; there are at least 10 other passengers on the 50-seater bus making the same trip.

Moneychangers walk around carrying wads of Syrian currency, as passengers smoke argileh, drink coffee and wait for departure time. Bus drivers shout "Damascus! Aleppo! Raqqa!" to entice passers-by. A poster advertising the bus station reads: "Feel safe with us."

At around 7:30am, the engine roars; driver Abu Hamad calls on passengers still ambling outside to take their seats. A few minutes later the bus is gone, beginning a journey that spans anything from 20 hours to three days, passing by government-held territories and opposition armed groups-manned fronts, til it reaches the heart of ISIL-held territory.

In some ways, those who make the trip are the first to witness Syria's changing borders.

Usually we have no problems with Daesh because we come prepared. I pull over, they come into the bus, and check everyone's ID, and if they don't have a problem with anyone, we can go. Abu Hamad, bus driver The Charles Helou bus station, completed in 1974, was meant to transform public transport in Beirut at a time when rural migrants, coming from different parts of the country, were moving to the city in hordes.

Located under the main highway connecting Beirut to the coastal road north, the station was designed to ease the flow of traffic in the downtown district. "The highway and the station were built across a bay, connecting two seaside outcrops," said Abdul-Halim Jabr, an urban planner. "The area was basically a cliff."

With the start of Lebanon's civil war in 1975, plans for the station came to a halt. "During that time we heard stories of people being thrown from the upper highway to the lower street," he said. "This bus station has a gruesome history."

Fifteen years after the war ended, and despite plans to rehabilitate the station, it appears to be a phantom of its original, buoyant, purpose: Bathrooms are unhygienic, management of the station is in disarray, and its most dedicated patrons are not Lebanese migrants, but Syrians returning to their embattled towns.

A ticket to Raqqa costs around $50. To stop off in Aleppo on the way, passengers pay $30.

"It's cheap because the people who go are often poor," Ghassan, a manager in the ticket booth, said. "All buses go to Damascus in transit."

Like Umm Mohamed, most passengers are Syrian nationals, typically workers, going to visit their families.

Ibrahim, another passenger, said he had spent a week growing a beard to make the trip to see his mother. "Without it, they [ISIL fighters] won't let me in," he said. He works in construction outside Beirut and sends his mother some of his earnings every few months.

"Life there is hard, but she doesn't want to leave," he said. "But life in Lebanon is hard too."

According to Ibrahim, men, too, will change into loose fitting pants before the bus reaches the first ISIL-manned checkpoint, knowing the disdain the ISIL fighters have for jeans.

On several occasions, young men wearing tight-fitted pants were ordered out of the bus and told to "walk back to Aleppo," according to Abu Hamad, the driver.

Ibrahim, who was sitting on the pavement chain smoking, will have to throw out his cigarettes. The bus driver is already prepared. A heavy smoker himself, Abu Hamad is armed with air-freshener to spray the bus before entering ISIL-held territory.

"Usually we have no problems with Daesh [the Arabic acronym for ISIL], because we come prepared," he said. "I pull over, they come into the bus, and check everyone's ID, and if they don't have a problem with anyone, we can go."

Haysam Sinno, is another bus driver. "Every time I go, I feel like it could be my last," he said. "You see the destruction, in the main roundabout you see the severed heads."

Ibrahim seemed unperturbed by the reception they might receive by ISIL fighters manning checkpoints; it's the sporadic shelling along the road that terrifies him most.

"If there is fighting, the Syrian regime soldiers make us stop the bus and wait until it ends," said Abu Hamad, speaking casually of the clashes, as though they were an inconvenient rainstorm barring his path.

"It's dangerous to go there, for sure," he said. "But what can I do? I have to make a living, don't I?"

The bus departs from the station every other day and Abu Hamad makes the trip every Sunday. At most, he has 14 passengers at a time. It's a route he's been driving for 13 years.

Before ISIL's rapid advances in Syria, he recalled, the journey would take far less time. "We would leave Beirut by 10pm and be in Raqqa by 3am, now we leave at 7:30am and arrive around 3pm the next day," he said.

The important issue, he stressed, is to avoid driving at night. "That's usually when there are clashes." Instead of the direct route from Damascus, Abu Hamad must drive up to Homs, then to Aleppo, and from there take the road to Raqqa. But it's rarely a smooth ride.

On several occasions Abu Hamad's bus has been shot at while crossing frontlines; he has had to replace the windscreen twice and the side is still pockmarked with bullet holes.

"I keep driving straight," he said of such moments. "Sometimes I see checkpoints manned by gangs with a dangerous look about them, so I keep driving, I don't stop."

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Last year, heavy fighting near Safirah, on the way to Raqqa from Aleppo, forced Abu Hamad to park on the side of a road for three days. "Regime soldiers brought us food, and the passengers slept on the bus," he said.

But sudden road closures on the way back to Beirut are the greatest challenge for a bus driver in Syria. In such cases, Abu Hamad tries to take an alternative route via Salamiyah, in Hama, or worse, a convoluted path requiring a drive further north near the Turkish border.

Despite such circustances, some passengers still go further. Ahmed, a Syrian worker in Lebanon, is accompanied by his elderly mother.

He plans to drop her off in Mayadeen, a town in Deir Ezzor, eastern Syria, near the border with Iraq, where she will be reunited with her sister and son. "I told her to stay, but she misses them too much," said Ahmed.

Ahmed's oldest brother is in Germany. He was among the thousands who took the dangerous sea voyage from Turkey to Greece. His other brother is stuck in Aleppo, too afraid to brave the risk of air strikes to visit his home in Mayadeen.

"We are all divided," said the elderly mother. "But I came to Lebanon because my son was getting married."

Ahmed is accompanying her, knowing that he might not be able to return. He recently heard that ISIL was not permitting men between the ages of 15 and 45 to leave his town.

"She can't enter without a male companion," he explained. "Daesh has made it very difficult for us, but we can't protest, if I did my head would decorate our roundabout, along with the others who spoke up against it."

Additional reporting by Nazih Osseiran