The six questing mugs of Cupland

 All was quiet in Cupland.  It was the night, when the cups were safely cuddled up together with the Great Glass Barrier in place, protecting them from all kinds of nasty creatures.
  Most of the cups were asleep, but one cup, Mr 30, was awake.  He nudged his neighbour, Mr Blue.
 "Blue!" 30 whispered. "Are you awake?"
 Blue yawned.  "I am now."
 "I can't sleep, Blue! I'm too excited!"
 "Why's that?"
 "Because I love mornings!  And I'm right up against the Great Glass Barrier!  I might get out tomorrow!" 30 cried.  The grey insulated mug behind them shook a little, then fell back to sleep.
 "I know, 30."
 "Isn't it great?!?" 30 asked, but Mr Blue had fallen asleep again.

 Mr 30 did indeed get to go out in the morning, and was filled with lovely boiling water, with a bit of milk, coffee, and sugar stirred in.  This was how all the cups lived - they lived in the cupboard, hoping to get out, be taken around the house - perhaps even into the garden, weather willing - get a good scrub in the sink and a dry before going back in the cupboard with their friends.
 It was a good life, if sometimes a slightly boring one.  Mr 30 thought about Foamy the cup, who was right at the back of the cupboard.  Foamy had a big crack in him, which generally meant that a cup would mysteriously vanish and never be seen again, but instead Foamy stayed at the back of the cupboard, never to be used.

 "We have a serious problem," Mr Purple announced one evening, when the lights were out and the various strange pink walking things had left the kitchen.
 "There are less of us than usual.  I don't know where our friends have gone, but Spotty Cyan hasn't been seen for days.  Not to mention Yellowing and Big Flask."
 The other cups shuffled amongst themselves, clinking slightly.
 "We must investigate."

And so the quest was ordered.  An expeditionary force of six mugs was decided upon, to venture beyond the Great Glass Barrier to find their lost colleagues.
 Of course, the first obstacle was the barrier itself.
 "How do we get past it?" asked Blue.
 "Maybe some tea?" suggested 30.  But none of the cups had any tea.
 As the six cups discussed what to do, they were interrupted by some bickering.  They turned to see two mugs, one placed on top of the other, arguing.
 "Oh no," said Swearword, "Who put Black on top of Green? They never agree on anything."
 "I'VE HAD ENOUGH! I'M OUT OF HERE!" shouted Black, leaping up off Green and slamming straight into the shelf above.  The cupboard shook, but instead of the brief shake subsiding, it continued, and then an almighty shudder wrenched the cups around.
 The Great Glass Barrier flew open as a glass from the shelf around tumbled out, crying "You bast-" before smashing on the floor.
 "This is it!  This is our chance!" declared Mr Purple.
 The cups rolled carefully on their sides out of the cupboard and off the kitchen counter onto the floor, where fortunately the smashed remains of a glass made the landing slightly softer.
 "Where do we go now?" asked Swearword.
 "Up.  That is where the answer is.  We go up." decided Purple.

 And so the cups made their way upstairs.  It took them many hours, with each stair being a veritable mountain for the cups to climb, but eventually they made their way right to the top of the house.
 "What now?" 30 whispered.
 "We must visit our god." Purple declared.
 "You don't mean..." Blue said.
 "I do."

 The cups shuffled across the attic floor, moving as quietly as they could, until they were finally face to face with their god.  The one that they dreamed of.  The one that occasionally they got to visit, the one that sometimes hummed and sometimes beeped.
 They reached The Black Tower.

 Mike picked up the mugs, put them on a tray, and took them downstairs to be washed.

The end!