Daniel Sousa is an American soldier who fought during World War II. He had to abandon the warfield due to losing one of his legs, and became an agent of the Strategic Scientific Reserve within one of their offices in New York City where he was determined to prove his worth in spite of his disability. After helping to stop the terrorist plot of Johann Fennhoff, Sousa eventually became chief of the Los Angeles branch of the organization and soon found himself reunited with Agent Peggy Carter when they both began investigating the actions of Whitney Frost and her new interest in Darkforce, putting his personal and professional life into conflict. As they defeated Frost, Sousa and Carter became closer and eventually began a long overdue relationship.