The HST for the 05.46 EXD - Paddington went to rescue it at approx 04.15.
On arrival at EXD platform 6 at 06.34, the HST detached and left the sleeper in the platform. The passengers went forward on a spare HST which had been held at Dawlish Warren waiting events.
The 57 suffered a loss of oil apparently. Expect an additional daytime down run of Sleeper stock later - no detail yet.
Many thanks for this report Martin