Does a practice breakdown mean Crossrail is near?
It's the weekend, and along with a thousand other people, we are at Woolwich Crossrail station.
We are told to board a train and head off towards Canary Wharf. The train is full - mainly with Transport for London (TfL) employees and their families - but it is noticeably quicker than Tube trains and feels larger.
Over the Tannoy, the driver soon announces that we have "broken down".
Despite this, everyone is in good spirits.
After much coming and going from a British Transport Police officer and the driver, a rescue train is brought in and we are all marched on to that train, which takes us to Canary Wharf.
Most tell me the experience goes smoothly.
After 10 minutes the alarms go off and we all evacuate the station - again it is a safety drill.
Transport bosses are very tight-lipped about the exact opening date; they are clearly working to a number of options before the end of June.
So what does this trial evacuation show? It was a big step forward and the opening can't be far away.
Rebecca Edwards, who is in charge of the volunteers, says the regulator, the Office of Rail and Road, needs to see that TfL can evacuate a train safely in order for Crossrail to receive the required safety certificates.
There have been many hiccups, delays and overruns but will London now get its Elizabeth line?