Julius and the Watchmaker by Tim Hehir Page A

follow?’
    â€˜Eh…?’
    â€˜Now we will complicate matters a little by introducing a time-traveller who is not constrained by that one timeline. Imagine a time-traveller going back a week in time and changing something, anything. You would represent that by drawing a line on the tablecloth beginning at the end of your line and going diagonally backwards to a point that is a few inches to the left of your original dot. That is your changed past. Now, to let that changed past continue along its natural course you would draw a line straight along the length of the cloth and stop when you draw parallel with the end of the original line. This point is the new present. It is a different present because it has a different past—and it will have a different future. So you see our dilemma. We now have two presents running parallel. Each present is inhabited by the same people but they are living in different realities. So my question to you, Julius, is: which is the real present?’
    â€˜Um…’
    â€˜You’ll never get it, so I’ll tell you. They are all real. One is actually real and the rest are potentially real. There is one original timeline on which all the others are but branches.’
    â€˜Er…’
    â€˜So, that leads us to possible and probable futures and pasts. Forget about the tablecloth for a moment, and think of a tree. The single trunk is the present in this timeline—the timeline we time-travellers have sworn to protect. The splaying branches, each leading to ever smaller branches, represent the future. So let us take a journey into the future. The single trunk divides into two, or three, or four branches. These are where the normal course of time is altered by time-criminals out for personal gain, or by time-travellers like me trying to deal with them. Each fork in a branch is an alteration to a timeline. And so on and so on until you have literally millions of possible and probable futures. One of them is our actual timeline, all the others are potential timelines. If I, as a time-traveller, were to travel far forward in time to the end of one of these branches I’d have no way of knowing how many branches had sprung up before me. Are you with me?’
    â€˜I think so,’ said Julius, not completely sure. ‘Go on, Professor.’
    â€˜The branches closest to the trunk are the probable futures. That is, I can travel a little forward in time and gather information and I can be relatively certain that the future I am in is a probable result of the past I just left. The further I go out in time, the further I go out in the tree’s branches. The ones further out are possible futures. I could travel to them but have little or no reliable information to help me with my present problem. For instance, I once found myself in a possible future where boys and girls sat all day in darkened rooms staring, like the dead, at illuminated moving pictures that crashed and hissed as they manipulated the infernal device to kill and maim their fellows represented on the pictures. Clearly this is some preposterous possible future which is the result of some diabolical interference by a time-criminal somewhere in the future. I only hope we can be there to deal with it when the interference occurs.’
    â€˜So…so we can go back to London to…?’
    â€˜Ah, that leads me to your original question, Julius…It’s not quite, back .’
    â€˜I don’t understand.’
    â€˜I have something in the way of a confession to make, Julius.’
    â€˜Me too,’ said Mr Flynn. ‘Hold on to your hat while you listening to the next bit, young fella.’
    â€˜You see, Julius, my boy…how can I put it? Our adventures in London, the Grackacks, the enquiry at Mr Higgins’s bookshop, all that, well, they haven’t happened yet.’
    â€˜What?’
    â€˜I can see that you are somewhat dismayed, Julius. I can understand