Staring earnestly into the camera in an open-neck shirt, with the sleeves rolled up to the elbow, Christopher Berry extols the virtues of West Lake, the chief tourist attraction in Hangzhou, a city of 13 million in eastern China.
"Hi, I'm Chris from Oxford in the United Kingdom," announces the man accused, until recently, of spying for China, before a clumsy cutaway whisks the viewer to an endless montage of shimmering water, tree-lined causeways and rolling hills.
Over eight meandering minutes, Chris from Oxford talks of West Lake's views and history, of the poets who lived on its shores and of the two bouts of dredging that shaped its contours.
The lake, he concludes, is "the idealised fusion between man and nature", one that "allows people to project feelings onto its landscape".
To all appearances, it is the work of an underpaid English language teacher supplementing his income by making promotional videos for the Hangzhou municipal council.
But Mr Berry was suspected of espionage during the time that the video was published. Authorities waited for him to return to Britain on holiday in 2023, then arrested him alongside his friend Christopher Cash, a parliamentary researcher who had taught English at the same Hangzhou school in 2018.
Both men were charged under the Official Secrets Act in April last year with providing Beijing with information potentially "prejudicial to the safety" of the UK. They denied the allegations and the case collapsed last month after prosecutors failed to obtain witness statements from government officials attesting that China posed a threat to national security.
Mr Cash has attracted greater scrutiny and attention because of his access to the House of Commons as a researcher for Alicia Kearns, the Conservative MP, while she chaired its foreign affairs select committee.
But investigators claimed that it was Mr Berry who sat higher in the chain of command.
According to the Crown Prosecution Service, an individual identified as "a Chinese intelligence agent" commissioned at least 34 reports from him on matters of political interest. Mr Berry, in turn, allegedly obtained information from Mr Cash and incorporated it into reports for the agent, who then passed them on to a "senior member of the Chinese Community party (CCP) and a politburo member".
That information was said to have been "sensitive" rather than classified - details such as hotel room numbers for MPs, including Ms Kearns, during a foreign affairs committee trip to Taiwan in 2022.
British prosecutors suspected that the ultimate recipient of the intelligence was one of China's most senior officials, the Guardian reported last week. That man is believed to be Cai Qi, the fifth-ranking member of Chinese Politburo's main standing committee and the de facto chief of staff to Xi Jinping, China's president.
Mr Cai was Hangzhou's mayor between 2007 and 2010 before rising through the provincial hierarchy. His son, Cai Erjin, worked for the municipal office that oversaw the school where Mr Berry and Mr Cash worked.
Both men would doubtless dismiss this as coincidence. In a city as vast and bureaucratic as Hangzhou, it is far from implausible that they never encountered the Cai family.
The Cai family are indeed well-connected. Lin Chengsheng, Cai Qi's wife, previously served as the deputy director of the Taiwan affairs office in Zhejiang province from November 2012 to April 2014, during which time she also travelled to Taiwan at least twice.
Among the material that Mr Cash and Mr Berry allegedly passed to Mr Cai were details of a foreign affairs committee delegation that travelled to Taiwan in November 2022.
Mr Cai also travelled to Taiwan in July 2012 while serving as a member of the standing committee of the Zhejiang provincial party committee.
Mr Cai made headlines in China in November 2024 when reports surfaced that Cai Erjin had been detained after suffering a car crash, which some alleged was an assassination attempt.
Local Chinese media claimed that he had been put under investigation by the central commission for discipline inspection, the highest internal control institution of the CCP.
The incident took place as news broke that Miao Hua, a member of China's central military commission and the head of its political work department, had been suspended as part of Xi's ongoing purge that was dressed up as an "anti-corruption" campaign.
Little is publicly known about exactly what Mr Cash and Mr Berry did in China. What is certain is that Mr Berry worked at Hangzhou Dongfang Middle School between 2017 and 2019, while Mr Cash spent a year there in 2018.
Mr Cash, now 30, later returned to Britain and joined the Chinese Research Group, set up by Beijing-sceptical Conservative MPs in April 2020 and chaired by Tom Tugendhat, who later joined the Cabinet. Ms Kearns succeeded him in September 2022. Impressed by Mr Cash, a fluent Mandarin speaker, she secured a parliamentary pass for him so that he could be more readily available.
He was, she later said, "very capable" - someone who loved China but was always critical of the Communist Party.
At the same time, prosecutors alleged, he was passing information about the group's activities to Mr Berry in Hangzhou.
According to the CPS, Mr Berry submitted reports to his Chinese handler between December 2021 and February 2023.
If the claims have any basis - which both men strenuously deny - the intelligence gathered was probably of limited value, analysts say, as neither had access to classified information.
Kerry Brown, the director of the Lau China Institute at King's College London, said: "I come back to this issue of what these individuals would have known given what we know about their status. They didn't have security clearance and they weren't working in an absolutely key part of government that was dealing with actual China policy."
The enigma of the man in the video may now never be solved. He may have been, like his friend, a hapless innocent abroad caught up in a nightmare not of his own making - or a master of subterfuge, a reincarnation of the Cambridge Five as the Oxfordshire One.
The spy case regarding Mr Berry and Mr Cash was, in the end, never tested in open court, ensuring that questions surrounding the case will rumble on for months to come.