Route notes
Why this routing works
This itinerary is built as a compact North America multi-stop from London, using Montreal twice: first as the arrival point from the UK, then again as the final North American stop before the return to London. That sequencing keeps the route linear and avoids backtracking beyond the planned revisit to Montreal.
With 1 night in Montreal, 2 nights in Chicago, and 2 more nights in Montreal, the timing suits a short one-week trip where flights and stop lengths need to stay tightly coordinated. The second Montreal stay functions as a deliberate stop rather than just a same-day connection, which is useful when structuring a brief open-jaw style city sequence within a single ticket.
In economy, this kind of multi-stop ticket is best understood as a way to bundle several flight segments into one organized routing rather than pricing each leg separately. January departure timing places the trip in the Jan-Mar season.