BLUE lights flashing, a waiting police van roared into life as it prepared to drive alleged rogue trader Kweku Adoboli into custody from his home in Bethnal Green, London, in the early hours of last Thursday.
And inside a building on Finsbury Avenue in the heart of the Square Mile, Adoboli's employers at UBS knew that the Swiss bank was about to be rocked to its foundations -- again.
The drama unfolding at UBS's London headquarters was the worst nightmare for a management which have been striving to restore the bank's reputation.
During the credit crunch, UBS was left reeling. It was bailed out by the Swiss government after being forced to write down $50bn (€36bn) linked to US mortgage-backed securities in 2008.
It faced charges in the same year of providing services to American clients seeking to evade taxes and was fined nearly $800m (€580m) by the US authorities in a long, tortuous case that heaped shame upon the Swiss financiers.
More recently, it seemed that UBS was putting many of its problems behind it as it returned to profitability under chief executive Oswald Grubel, albeit against the difficult backdrop of the growing crisis in the eurozone.
Now it faces more turmoil than anyone could have imagined, after the disclosure that a rogue trading scandal has cost the bank about $2bn (€1.45bn) and Mr Adoboli's charge sheet alleges that the misdemeanours might stretch back to 2008.
Mr Adoboli, a derivatives trader and former public school head boy, was charged with fraud and false accounting on Friday and will appear in court on Thursday. There was no request for bail and he was remanded in custody.
The case revives memories of Nick Leeson, who lost £800m at Barings in 1994, and Jerome Kerviel, who cost Societe Generale €4.6bn.
The wonder of the latest scandal is that it happened at a bank which prides itself on probity and conservatism, an image fostered to attract the global rich to its "wealth-management division".
Once a pillar of the Swiss establishment, UBS can be prudish in the extreme. In 2010, it published a 44-page dress code for staff (withdrawn this year) that exhorted women to wear skin-coloured underwear and advised men to have monthly haircuts and trim their beards.
The guide is thought to have been developed by executives as part of UBS's attempts to improve its image.
Other gems include: "You can extend the life of your knee socks and stockings by keeping your toenails trimmed and filed."
Another says: "Glasses should always be kept clean... this gives you optimal vision and on the other hand dirty glasses create an appearance of negligence."
Now the bank is engulfed in another large, embarrassing controversy that has sparked speculation it could offload its investment-banking arm, which employs 6,000 in London -- including Mr Adoboli.
It was the investment bank that plunged UBS into multibillion-pound losses during the credit crunch because of its exposure to toxic US sub-prime mortgages and related derivatives, such as collateralised debt obligations.
Today, the same unit is at the centre of an inquiry on opaque exchange traded funds (ETFs). These complex products allow speculators to bet on price rises or falls in a vast range of indices, currencies and commodities, from the FTSE 100 to gold and even "leveraged live cattle", without having to buy the shares or commodities directly themselves.
Commentators said it was remarkable that the scandal had been uncovered in the same week as the publication of the Vickers report on UK banking reform, which proposed that banks' high- street operations should be ringfenced from riskier "casino" investment banking.
"It could have been written with UBS in mind," commented one analyst.
UBS can trace its roots to 1854 and is one of the world's largest managers of private wealth. With 64,000 employees based in more than 50 countries, the bank is the product of numerous mergers and acquisitions, including deals that brought on board the British stockbrokers Phillips & Drew and blue-chip City bank SG Warburg.
It emerged in its present form after the 1997 mega-merger of Union Bank of Switzerland and Swiss Banking Corporation. Another landmark deal followed in 2000 when the merged group acquired Paine Webber, an American brokerage and asset-management firm.
But for all its conservative airs and graces, UBS has never been far from controversy. It reported the highest losses of any Swiss company in 2008 when it plunged $17bn (€12.3bn) into the red and wrote down $48bn (€35bn) in sub-prime and other mortgage assets. More than 20,000 jobs were lost and the dividend was cut to protect the bank's traditionally high core capital ratio -- seen by investors as a key to its credibility as the world's largest wealth management company.
Senior directors fell on their swords and at the height of the crisis UBS launched a rescue rights issue to shore up reserves.
In July 2008, a US Senate panel accused UBS of enabling wealthy Americans to evade taxes through offshore accounts. After an FBI investigation, UBS announced that it would cease providing cross-border private banking services to US-domiciled clients through its non-US regulated subsidiaries.
The bank agreed to pay $780m (€566m) and entered into a deferred prosecution agreement on charges of conspiring to defraud the US by impeding the Internal Revenue Service. The day after settling its criminal case, the US government filed a civil suit against the bank to reveal the names of all 52,000 American clients. It was not until June 2010 that Swiss lawmakers approved a deal to reveal client data and account details of Americans who were suspected of tax evasion.
The tax row seriously damaged UBS's reputation and worried customers moved their funds. Analysts said more than $200bn was withdrawn. UBS reported a return to net inflow recently -- but that may change if Mr Grubel fails to contain the crisis.
In Switzerland, the rogue-trading scandal is playing badly with politicians, many of whom have been looking for an excuse to force UBS to abandon investment banking and concentrate on retail and wealth-management services.