Possible caustic crossing in system 1. Top: Color image combining F090W, F200W, and F356W as blue, green, and red, respectively. Bottom: Color image in the RGB6 pallette with critical curves from the spectroscopic, Full-r, and Full-a models shown as red, green, and blue, respectively. In both images, the two yellow circles mark images 1.3a and 1.3b, a pair of counterimages close to the expected position of the critical curve. The white circle contains a faint source that is barely resolved.