In The Taproom Of The Old Phoenix

Entering the Old Phoenix from one version of seventeenth century England, Will Fairweather closes the door against the storm.

"Windows likewise were tightly shuttered."
-Poul Anderson, A Midsummer Tempest (London, 1975), Chapter xi, "THE TAPROOM OF THE OLD PHOENIX," p. 90.

Will and his companion, Prince Rupert of the Rhine, must think that the windows are shuttered against the storm that they have just evaded whereas, in fact, the next time the door is opened, it may not be onto that storm or even onto that scenery while the windows, if opened, would show the void between the universes or maybe a cross-section of multi-dimensional space.

Their host addresses them in what looks like prose but can be rearranged as verse:

"What may your wishes be? Nay, let me guess.
"Ye've fared through rain, in striving and distress.
"A bath, dry garb, hot food, a cup of cheer,
"A bed, then breakfast , ere ye go from here." (p. 91)

Another guest, Holger, claims that giants existed in his timeline but his example is the seven-foot Harald Hardrada so, on that evidence, his timeline could be ours! His companion, a young woman, remarks that his and her worlds were similar or identical till about 1900 and that Abraham Lincoln might visit the inn. This is the first hint to the reader that time travel or something like it is involved. We are used to the idea by now but it is always worthwhile to check how an author first presented such notions.