She was looking for her bag when she realised she (leave) it in a café.
had left
When I (wait) at the security check, an official (ask) me to open my bag.
was waiting - asked
I had a red face because it was hot and I (run).
had been running.
A strange thing (happen) to me while I (wait) at the bus stop.
happened - was waiting
They (walk) away from the house when they (hear) a police siren.
were walking - heard
A police officer (stop) him just as he (open) the car door.
stopped - was opening
By the time I arrived they (go) home.
had gone
While she (open) the bag, she suddenly realised it (not be) hers.
was opening - wasn't
At first I didn’t realise he (take) my bag instead of his.
had taken
The police said they (watch) the house for days.
had been watching