At Salisbury cathedral, preparations are under way for next weekend’s Advent procession, Darkness to Light. The event begins with the magnificent gothic cathedral in total blackness and silence. A single candle is lit, followed by another and another, until the whole interior is illuminated by 1,400 flickering flames.

“The Advent message is that darkness is always overcome by light, despair is always overcome by hope,” the cathedral’s dean, Nick Papadopulos, told the Observer. “We are trying to shine light into the darkness of the year coming to an end.”

This has been an annus horribilis for Salisbury. In March, the city was thrown into the global spotlight when Sergei Skripal, a former Russian double agent, and his daughter Yulia were found slumped on a bench after being poisoned with the nerve agent novichok.

The city centre of Salisbury was effectively locked down as investigations and decontamination took place. Then in July, just as confidence was beginning to return, Wiltshire residents Dawn Sturgess and Charlie Rowley fell ill after discovering a fake perfume bottle which had contained the agent. Sturgess died; Rowley is still suffering the after-effects of poisoning – as is police office Nick Bailey, BBC Panorama revealed last week.

The impact on the city has been devastating. But as the end of the year approaches, there is cautious hope among residents, traders and local leaders that the worst is behind them. Most people simply long for Salisbury’s reputation to revert to that of a quiet medieval city with a stunning cathedral rather than the stage for a far-fetched espionage murder plot reminiscent of a cold war thriller.

“It wasn’t obvious at first that we were going to go through an economic shock,” said Pauline Church, a cabinet member of Wiltshire council with responsibility for economic development. “But our footfall went down by 25% at one point. Now we’re still 10-12% lower than this time last year.” There was a danger Salisbury would be forever associated with the poisonings, she said. “We don’t want to be known for this.”

The attacks represented a double whammy for Salisbury, like other urban centres already facing the challenges of internet shopping and rising costs. The county council is now working on a two-to-three-year project to elevate “experience” over retail.

In the short term, it has pumped resources into a Christmas market and ice-rink, taking adverts in national newspapers inviting readers to “celebrate Christmas with us”.

Sergei and Yulia Skripal in Zizzi. Photograph: REX/Shutterstock

“We’re hoping this will be our busiest year,” said Church. In Ganesha, a shop selling crafts and jewellery close to the bench where the Skripals were found, manager Poppy White is pinning hopes on a Christmas surge. “We lost 75-80% of business for a while, and I personally lost at least 100 hours of pay,” she said. “We’re still not back to where we were; it’s on-off. This week has been abysmal.

“If it doesn’t pick up in the run-up to Christmas, the shop may close. It’s incredible: someone in Russia decided someone else needed to die, and I could lose my job as a result.”

At a seafood stall on the spot where the potentially novichok-contaminated bench once stood, “Henry the cockle man” – as he introduced himself – said business was picking up slowly. But, he added, “every time they bring [the poisonings] up in the newspapers or on the telly, they kill us all over again.”

There was better news in Zizzi, the Italian chain restaurant where the Skripals dined after being poisoned. It closed for eight months. Since it reopened this month, “a lot of people have been coming in to show support – and they keep coming back,” said manager Joe Pegg. The restaurant was 50% busier than before the poisonings, he said.

The cathedral has also suffered. “After the attack, visitor numbers plummeted to 29% [of the same period in the previous year]. It was a very substantial hit. Then we had the second incident, and we were hit again. This month, we’re down about 8% [compared to last November],” said Papadopulos.

The cathedral, which does not charge for entry but encourages donations, has been forced to rely on other sources of income to make up the shortfall, he said. Papadopulos was appointed dean of Salisbury cathedral in February, about a month before the Skripals’ poisoning but did not take up his post until September. “When I accepted the job I had no idea I’d be coming to a city at the centre of a global news story,” he said. Last month, there was yet another commotion when a man armed with a hammer tried to steal the cathedral’s Magna Carta from its glass display box. He was accosted and detained by members of staff. “It was a very shocking thing,” said Papadopulos.

Throughout the city’s dramas, the cathedral has been an important symbol of constancy, he said. “It has been on this site for almost 800 years, though wars, civil wars, black death – everything history has thrown up. Throughout we have said our prayers; the heartbeat continues.”