In the Unbound Universe, a disgraced Brigadier Lethbridge-Stewart moved to Hong Kong.
On 30 June 1997, when the city was due to be turned over to China, the Master fled to the city, allegedly to defect back to the British but actually sought to take over the Ke Le Divisions and China. Having recently crashed in Hong Kong, the Doctor struck a deal with the Master, agreeing to give him a lift aboard his TARDIS if he let the UNIT force evacuate before the Handover.
When the group reached the waterfront, the Master betrayed them. Anticipating this, the Doctor duped the Master into The Little England pub while he and Lethbridge-Stewart took off in the TARDIS to dispose of the last mental parasite in Mongolia. Having discovered he'd been duped in time to watch the TARDIS take off, the Master tried to get a ride from Colonel Wood only for the parasites to be destroyed, causing the Ke Le Divisions, having been waiting for the Master, to go insane and open fire on the crowds as they celebrated the Handover. (AUDIO: Sympathy for the Devil) By one account, the Doctor and Lethbridge-Stewart eventually returned to the city for a peaceful retirement, helping the Sixth Doctor and Evelyn Smythe when they had crossed universes. (AUDIO: The 100 Days of the Doctor)