Final answer:
The alchemist was likely observing the people entering the oasis from the caravan to observe omens and signs and seeking potential disciples.
Step-by-step explanation:
The alchemist was likely observing the people entering the oasis from the caravan to observe omens and signs. In the provided text, it mentions that the alchemist was waiting for an event to witness marksmanship. This suggests that he is skilled in interpreting signs and may be specifically looking for signs related to his area of expertise, which could be alchemy or divination.
The alchemist may also be seeking potential disciples. By observing the people entering the oasis, he may be looking for individuals who possess certain qualities or characteristics that align with his teachings or beliefs. This could be an opportunity for him to share his knowledge and guide others on their spiritual or philosophical journey.
It is unlikely that the alchemist is guarding against intruders or simply enjoying the spectacle. These reasons are not mentioned in the provided text and do not align with the alchemist's role or purpose.