Malaysians who are visiting Singapore today or the next Sunday and using the trains will do well to prepare for sudden explosions that may resemble a bombing attack.
It will be the republics largest civil emergency exercise to test how prepared everyone the civil defence forces and the public is to a bombing or gas attack that the city has long felt will happen one day.
With the economy recovering well, the authorities are taking security a step further.
The three-hour test will be as close to the real thing as possible without bringing life to a halt and will be centred around mock bombings on four MRT stations and a bus interchange.
Thunder flashes that can produce loud explosions and smoke generators will be used. Police will immediately launch a hunt for the bombers.
These stations may be forced to shut down. Special buses will provide alternative service to thousands of stranded passengers.
Singaporeans had been readied for this for some time but without being told exactly when or where the bombs will go off.
Some 1,300 government officials, seven restructured hospitals and two polyclinics will be involved.
Fifteen field medical teams comprising 24 doctors and 48 nurses will move to the stricken areas in three waves to handle 500 casualties.
It is part of an elaborate security net gradually built around the island since it uncovered a plot by Jemaah Islamiah militants (31 were detained) four years ago to blow up foreign embassies and strategic installations.
It was done with quiet efficiency without panicking the public or upsetting investors or unsettling Singapores 15% Muslim minority. This occasion, however, it will stir up the public in a dramatic way as intended.
Used to a lifetime of tranquillity, Singaporeans are finding it hard to suddenly gear themselves up to fight a terrorist war.
Most people believe they are well protected by the government, an apathy that could pose a danger to the survival of this over-crowded city, which is considered a terrorist target.
Despite frequent reminders, few commuters are worried enough by or report suspicious people or packages left in train or bus terminals.
This three-hour exercise is not only designed to measure the readiness of the civil defence and hospital personnel to cope with a major disaster, but also the response of the public.
In an attack, much will depend on how the victims react.
Some cynics say that, coming close to a general election, the ruling party has timed it to divert attention away from bread-and-butter concerns to security issues.
Perceived threats always work to its advantage since voters will opt for safety, one writer remarked.
Few Singaporeans, however, think that. Singaporeans see terrorism as their biggest threat and generally give the government high marks for a comprehensive programme that goes beyond just security measures.
With the militants all claiming to act in the name of Islam, the government with the help of Muslim leaders has quickly moved to reassure the population that the dangerous elements are a small minority.
When the 32 JI detainees were found to include middle class, well-educated Malays, including national servicemen, it shocked the nation. That Singaporeans were prepared to blow up installations and kill their own kind had surprised people of all races.
The immediate efforts were to allay fears of the Chinese against their Malay neighbours and, at the same time, assured the Muslims that the security measures were aimed at a few, not the whole community.
Community representatives especially the Malay and Islamic leaders did much of the work, spanning out into the heartland to work among residents and schools.
A China correspondent commented, Singapore has adopted a moderate anti-terrorism approach towards Muslims in the country and the world as a whole.
Internationally, it advised the US-led anti-terrorism coalition to resort to soft power to win.
Inside the country, it has used persuasion and knowledge of Islam, not force, to change the minds of the detainees, allowing them to further their studies so that they can be rehabilitated.
With the breadwinners gone, needy families were given financial support by community leaders; their childrens education was cared for.
All these were not available to communist or leftwing detainees in the past, who were subjected to a harsher treatment.
But security was rarely overlooked.
Muslim teachers in Singapore have to be accredited by a panel of Muslim leaders before they can preach in mosques or teach in a religious madrassah school. Those who have spent time studying in Pakistan are under surveillance.
In the past year the city adopted a series of new measures, including deployment of special police forces to patrol public transport and crowded areas and land and sea checkpoints.
A new National Security Coordination Secretariat under the Prime Ministers Office was set up to handle unconventional attacks or threats.
Iris recognition machines, radiographic equipment and crash barriers were installed at land checkpoints to enhance cargo screening and the security clearance of motorcyclists and vehicles.
Singapore is reported to be planning the development of an early warning system that a futurist says could make it a model of preparedness against security threats.
Like a long-range radar, this computer-based system can spot a potential threat long before it looms large, said Mr Rohit Talwar, who heads British research and consulting firm Fast Future Ventures.
Ultimately, it is the ordinary folks who will decide if the war is winnable.
o Seah Chiang Nee is a veteran journalist and editor of the information website littlespeck.com