The Butler, Wandering is Chapter 170 of the Kuroshitsuji manga.
Summary[]
Several weeks before the investigation at Heathfield Manor comes to a conclusion, Ciel and Lau discuss how they will proceed to stop Undertaker and "Ciel": They have identified four locations east, west, south, and north of London that may be blood-collection facilities. To investigate each of them in as little time as possible, they will split up with Mey-Rin and Ran-Mao going north to North Yorkshire, Finnian and Snake going east to Norfolk, Baldroy and Lau going west to Wiltshire, and Sebastian and Ciel going south to Brighton. However, as Ciel and his servants are currently wanted by Scotland Yard, officers must be stationed at every major railway station. Lau suggests to leave London by boat on the River Thames as the security is lighter there and head to Reading where they would then continue their respective journeys by train. Sebastian also remarks that they should leave as soon as possible as Arthur Randall is aware of Ciel's and Lau's relationship and it is, thus, only a question of time when Scotland Yard will search the opium den.
Sometime later at night, they load the boat, but right before they leave, Lau takes out a box and asks Ciel and his servants to put on a flower hair ornament.
When they have almost passed through unfinished Tower Bridge, they are stopped and controlled by Scotland Yard's Thames Division. Lau greets them and tells them that he is only delivering "flowers." One of the Thames Division officers inspects the ship and finds the Phantomhive household huddled together and wrapped in blankets with only their faces and flower headpiece partially visible. Upon seeing them, the officer understand what Lau meant with "flowers," and Lau hands him a few coins to buy hot drinks in this cold night. Afterward, the officer leaves, and everyone pulls down their hoods. Sebastian remarks that he is quite astonished that this diguise has worked; after all, he and Baldroy do not look like women at all. Lau then says that not only the headpiece has helped them, but that the Thames Division is a highly independent division from the Metropolitan Police and, thus, Lau has been "friends" with them for some time.
At the Reading railway station, everyone says their goodbies before heading to their needed train. In their wagon, Baldroy scrutinises Lau as he feels rather uncomfortable in his presence as he can never guess what Lau is thinking. Then, Baldroy takes out a metal tin, and Lau muses that their adversary must be very formidable if Baldroy is dabbling in "that" as his "final resort." Baldroy replies that it is only candy Ciel bought him. Chuckling, Lau asks whether he can have one then.
After a while, Baldroy sighes, and Lau comments that he looks "somewhat depressed." Baldroy affirms this and explains that a sanatorium is barely different from a workhouse and is a place of death.
When they arrive at the Athena Sanatorium for Former Servicemen, Baldroy is, therefore, quite suprised when he sees that the building is not bleak at all. Before they go inside, Lau goes through their roles again: Baldroy is Mr. Burgh, the second son of an aristocrat who has returned home after getting injured in a colonial conflict, and Lau is his private physician who was hired as Burgh's experiences have left him very traumatised.
Afterward, Baldroy and Lau enter the sanatorium, and Lau greets a nurse and introduces "Mr. Burgh," who will be admitted today, to her. The nurse tells them to follow her and guides them to a waiting room where they would have to remain until the arrival of the chief nurse. The nurse leaves, and Lau wonders if the chief nurse of the "miracle nurse" and if she is a beautiful angel. Baldroy replies that, to soldiers, all nurses are angels. In the middle of their conversation, the door opens, and, to Baldroy's and Lau's shock and surprise, five people in protective clothing enter.