The individual title of each volume of Neil Gaiman's The Books Of Magic is given on the title page but not on the front cover so they come as a surprise. Book Four is The Road To Nowhere (New York, 1991). Mr E and Timothy Hunter, like HG Wells' Time Traveler, visit the near, then the far, future.
When asked whether he can travel into the future, John Constantine replies:
"Only like everyone else, boss. You know. One minute at a time." (p. 4)
One minute per minute is enduring, not traveling. Travel requires two kinds of units, e.g., one mile per minute. One objective century per one subjective minute would be time dilation, not time travel, although, in certain circumstances, this is called "time travel." I discuss this on the Logic of Time Travel Blog.
I think that E contradicts himself. He insists that they are truly in the future, but then unhelpfully adds "...or futures" (p. 5), but then says that what they are seeing is only a possibility that may never happen (p. 7). He describes the future as many possibilities, none of them definite, and explains that time travelers visit only the most probable. It follows that time travelers setting off from different times will travel through different futures. This contradicts Merlin in Book One definitely stating that his future was single, known by him and unalterable. I know that Merlin was in our past but he was talking about his future.
There will obviously be a lot more to post on this topic.
