unseen or less visible aspects of his work that are not easily noticed or understood by his crew or others. It suggests that his true contributions or challenges are not apparent from a superficial glance.

metaphorical parts behind him, within the brooding gloom" refer to the unseen or less visible aspects of his work that are not easily noticed or understood by his crew or others. It suggests that his true contributions or challenges are not apparent from a superficial glance.metaphorical "parts behind him, within the brooding gloom" refer to the unseen or less visible aspects of his work that are not easily noticed or understood by his crew or others. It suggests that his true contributions or challenges are not apparent from a superficial glance.