Theory:Torchwood television discontinuity and plot holes/End of Days


 * Captain Jack Harkness has traveled with the Ninth Doctor in the TARDIS. According to the Ninth Doctor the TARDIS telepathic field gets in your brain and translates for you (DW:The End of the World), but Jack makes no indication he can understand what the Roman soldier is saying.
 * It is very likely that the TARDIS must be nearby for the translator to work, just as it is dependent on the Doctor himself being nearby and conscious, as in DW: The Christmas Invasion, Rose, Harriet Jones, and Mickey couldn't understand what the Sycorax were saying until The Doctor was awake. Plus, as Jack spent many years absent from the Doctor and the TARDIS since DW: Parting of the Ways, so the telepathic field may have worn off (remember, this story is BEFORE DW: Utopia).
 * All maybe its as simple as that Jack knows latin!!
 * How come when it zooms out and has the aerial shot of Cardiff bay at the end it doesn't have the TARDIS there.

the tardis left almost as soon as it had arrived so maybe it had already left by that time