Three word game ...

[classic33]

to worry about

 

[172traindriver]

at the tunnel

 

[classic33]

exit, as you

 

[172traindriver]

suffered a derailment

 

[PeteXXX]

and a bump

 

[classic33]

whilst travelling to

 

[PeteXXX]

hire Boris Bikes

 

[classic33]

before everyone else

 

[172traindriver]

can be bothered

 

[PeteXXX]

to find a

 

[classic33]

"key" to unlock

 

[172traindriver]

the secret box

 

[classic33]

, that would allow

 

[the_mikey]

the fabled "pigeon"

 

[jonyjony]

to travel south