"I have a spell that removes tiredness; it could let all of us walk quickly for as long as we're not sleeping, but if I prepared it that many times it would leave little room for other spells. Better to be slow and safe. I don't think I have anything that would let us travel faster; I can't teleport or let us fly or conjure horses, or magically conceal our tracks." Speaking of which, they had better start walking back towards the hill if they're going to be in time to heal Frodo and still move somewhere else before nightfall.
"In my world there are no undead armies but there are also no undead leading armies. Except liches, I suppose, and then only in stories - liches are evil undead wizards who did it to themselves. There's a story about a lich who led a giant undead army but that was a thousand years ago. I suppose a wraith leading the living isn't the weirdest thing I've ever heard of."
Something itches in his mind. "To be clear, when I say 'in my world' I mostly mean on the continent I'm from. I've met people who came from Garund, the continent to the south - it's only a small sea between the two - but there are at least two other continents with oceans in between and I have no idea what goes on there. Although powerful wizards can teleport between the continents, so there's a limit to how isolated they can get. And I'm sure I don't know most of what goes on at home either, but an army of undead I expect I'd have heard of, if there was one around right now."
"Should we move during the day or night? I was planning on sleeping through most of today, and now that I won't get to do that I really should sleep the following night once we get away from the hill. I'm the only one who can see magic but I can't always be on watch and anyway if the wraiths come within sixty feet where I can see them, at night, it's already too late. But their horses at least can see during the day - I don't know how far and how well horses can see..."
"I still don't understand their tactics. We can't hurt them at range - I took down one of their horses at five hundred feet with a summoned cat but they probably won't fall for that again and it can't hurt the wraiths themselves. They can follow us from a distance during the day, keep a watch on the hill to see us leave, then attack once night falls. Even if we see them coming and prepare to use fire, at night they have the advantage unless we get another miracle. And they fought me in daylight, so I still don't understand why they can't just take the ring while you're away and Frodo is unconscious, if it's true that they can sense it without needing horses. What's stopping them, Merry with a torch?"