Work in groups of 2.
On a sheet of paper or on Google Docs (Google Docs if you want me to check your work).
Draw a timeline with an event E. Event E can be anything like an incident, accident, surprise, trip, strange story etc.
Draw other events on the time line that happened before Event E.
Make a dialogue between A and B of 9 sentences.
Start the dialogue with A, who will tell about Even E.
Learn the dialogue and practice, you will enact it in class.