After Jacob's Assassination of Dr. Elliotson, Evie pays a visit to Lambeth and continue her Research with Miss. Nightingale in the part fifth of Sequence 5: The Lady with the Lamp.
As Evie reaches Lambeth, she finds Clara weak and unhealthy state. After she simply collapsed, Evie asks for any doctor nearby and suddenly a door open with Women asking her to bring Clara inside. Then this Women introduces herself 'Miss Florence Nightingale' and explains how the tonic are been replaced with counterfeits tonics, also asks Evie to bring the original Medicine and a proper prescription as early as possible.
Note: You have only 8 minutes to Complete the job, so better make it fast and avoid unnecessary fights.
After the cutscene, you have only eight minutes to get this Job done. First locate the Peddler and Steal his potion. Here you also have a side objective to complete the stealing without killing the peddler.
Now locate the pharmacist and defend him from the thugs. After killing all the thugs talk to the pharmacist and you'll notice the supplies are been stolen by a thug so now chase him down and then take the carriage full of supplies back to Miss. Nightingale.
This complete the fifth part of Sequence 5: The Lady with the Lamp.