- "I am the Atlantic Express... and this... this is the end of the line..."
- ―Prentice Mill[src]
The Atlantic Express was eventually made obsolete by the personal bathysphere system and the Rapture Metro, thus the Atlantic Express stopped expanding. However, Mill remained optimistic, reasoning that the "private vehicle craze" was only temporary and that customers would soon return to the railways. His company might eventually have been able to recover, but Mill chose to place the majority of his assets into the banking system of Rapture at Andrew Ryan's request. This was supposed to help pull Rapture out of its economic depression, but instead it only resulted in Mill's financial failure.
The threat of decommissioning and closure became increasingly apparent, and Austen Bathysphere Co. offered to buy out his company. Broke, and without family or friends, Mill relocated to Pauper's Drop. He later died there, and a shrine dedicated to Mill can be found along with one of his Audio Diaries.