When Kathryn Erbe went on real-life maternity leave, so did her character, Detective Alex Eames. For several episodes, Erbe’s part was drastically reduced or non-existent, and the police squad brought in a temporary replacement for Eames. This is a tricky proposition for any show: you don’t want to bring in someone that’ll turn the audience off, but you also don’t want the audience to like the replacement more than the star.
The powers that be behind Law & Order: Criminal Intent solved this dilemma by bringing in a relative unknown (Samantha Buck) and focusing a little more on Goren (Vincent D’onofrio) than usual. On first sight, Samantha Buck is a near physical opposite to Kathryn Erbe: Buck is tall, with striking red hair and blue eyes, and an ethereal quality. Erbe is short, with brownish hair and brownish eyes, and a solidly grounded, vibrant presence.
Buck is eight years younger than Erbe, and this was allowed to show in her character, Bishop. Instead of simply giving Eames’ lines to the new girl, the writers (mainly Rene Balcer) took an opportunity to inject something new: an ambitious young detective, anxious to make a good impression on the Major Case Squad, but saddled with as quirky and difficult a partner (Goren) as one could find. Her irritation with him showed through a number of times, usually for good reason. This made her just that tiny bit unlikeable (so no one would prefer to Eames), but still sympathetic.
It looks easy when you see it done like this. But at the pace TV shows get put together, writing a new character into the existing mix takes a combination of hard work and stressful choices, even when you have a few months’ notice. CI got it right.