“I imagine John Watson thinks love’s a mystery to me, but the chemistry is incredibly simple and very destructive. When we first met, you told me that a disguise is always a self portrait, how true of you, the combination to your safe – your measurements. But this is far more intimate. This is your heart, and you should never let it rule your head. You could have chosen any random number and walked out of here today with everything you worked for. But you just couldn’t resist it, could you? I’ve always assumed that love is a dangerous disadvantage. Thank you for the final proof.”

“The rule for working out prime numbers is very simple, but no one has ever worked out a simple formula for telling you whether a very big number is a prime number or what the next one will be. […] Prime numbers is what is left when you have taken all the patterns away. I think prime numbers are like life. They are very logical but you could never work out the rules, even if you spent all your time thinking about them.”

“I think prime numbers are like life. They are very logical but you could never work out the rules, even if you spent all your time thinking about them”

“Prime numbers are what is left when you have taken all the patterns away. I think prime numbers are like life. They are very logical but you could never work out the rules, even if you spent all your time thinking about them.”

“All pleasure should be a little bent, don't you think?”

“When I was your age — about, ooh, a thousand years ago — I loved a good bedtime story. The Three Little Sontarans. The Emperor Dalek's New Clothes. Snow White and the Seven Keys to Doomsday, eh? All the classics.”

“As long as you have life and breath, believe. Believe for those who cannot. Believe even if you have stopped believing. Believe for the sake of the dead, for love, to keep your heart beating, believe. Never give up, never despair, let no mystery confound you into the conclusion that mystery cannot be yours.”