Howling:Inter-dimensional travel after the Time War

We know that travelling "sideways in time", into other universes and dimensions, was definitely possible in the classic series. A very good indication of this is "Battlefield", where knights from a parallel continuum cross over into the Doctor's reality, once in the Dark Ages (when King Arthur dies), and again in contemporary times (Ancelyn, Morgaine, etc). It's also strongly implied that at some point in his future, the Doctor will travel into the Arthurian dimension and become known as Merlin. But in the new series, it's been stated that following the Last Great Time War, dimensional barriers around our universe (and possibly others) have sealed, making inter-dimensional travel nigh impossible in all time zones throughout history. So if these barriers are in place, how did all that dimension-hopping in "Inferno" and "Battlefield" occur? And I know it isn't strictly speaking canonical, but what about the Seventh Doctor's interactions with Death's Head, a cross-dimensional traveller, in the DWM comic strips? It should be noted that in one issue of Death's Head's regular series, the Doctor briefly went to the Marvel Comics universe. So how does all of this tie in with the Time War, and inter-dimensional travel being impossible for everyone, everywhere? EJA 09:49, April 9, 2011 (UTC)