As a detective tackling the crossword puzzle, the first clue that caught my attention was the phrase ‘indie pop duo‘, which suggests that the answer is the name of a popular musical group comprising of two members. Immediately, I remembered that the name Tegan and Sara has been making waves in the indie pop music scene for quite some time. Specifically, in the clue, the word ‘Tegan‘ acted as a pointer to the other member of the duo. Once I realized this, I found the answer ‘Sara‘ to complete the blank space. The duo is known for their catchy tunes and meaningful lyrics, which have earned them a devoted fan base over the years. In summary, my thought process led me to the answer ‘Sara‘ via a series of thoughtful deductions based on the clue’s wording and my knowledge of popular music.