|| !fmenv->can_use_stairs()

    // Monster is chasing player through stairs.
    fmenv->flags |= MF_TAKING_STAIRS;

    // Return true for monsters that can't use stairs (so that friendly
    // monsters adjacent to them can still follow you through stairs),
    // but don't tag them as followers.
    if (fmenv->can_use_stairs())
    {
        // Monster is chasing player through stairs.
        fmenv->flags |= MF_TAKING_STAIRS;

    // Clear patrolling/travel markers.
    fmenv->patrol_point.reset();
    fmenv->travel_path.clear();
    fmenv->travel_target = MTRAV_NONE;

        // Clear patrolling/travel markers.
        fmenv->patrol_point.reset();
        fmenv->travel_path.clear();
        fmenv->travel_target = MTRAV_NONE;

    mprf(MSGCH_DIAGNOSTICS, "%s is marked for following.",
         fmenv->name(DESC_CAP_THE, true).c_str() );

        mprf(MSGCH_DIAGNOSTICS, "%s is marked for following.",
             fmenv->name(DESC_CAP_THE, true).c_str() );

    }