...There was a click, a rumble and the bookcase slowly began to slide open...
Ooh, a cliffhanger, how exciting! I wonder what happened? Hang on, I was there, so I can tell you, can't I. I peered through into the secret doorway, brushed aside the tangly cobwebs, and saw a dark stone passageway that was full of mucky doings. I went inside. The walls were all wet and the floor was slippy. Splip splop splash went the drip drops from the ceiling, and there was a horrid smell like cheesy trousers, or like the man who lives round the corner from me, what works in the fish and chip shop.
I carried on warily - normally I would skip but, as I say, it was slippy so I thought it best to do my special wary walking, so that I didn't fall over and break my bum. Fortunately, it was still light enough to see where I was putting my feet, because the passageway was illuminated by phosphorescent veins of rock, which don't actually occur in nature, but always come in very handy for made up stuff on the telly.
Where would this strange tunnel take me, I wondered? Could it lead to a secret underground base, where some Machiavellian despot was preparing a devastating attack on civilisation? Might it deliver me to a lost prehistoric kingdom, where giant lizards held dominion, long hidden from the prying eyes of man?
No. It wouldn't. Before very long I saw light ahead of me: twin beams striking through the darkness. Then, around the corner, parked in the middle of a cavern, headlights stabbing through the gloom, was a number 73 bus. Now, this was odd, because the number 73 doesn't normally run on Tuesdays.