Upon helping the couple, they shall give you Rat Bond blueprints.
Rat Bond Blueprint
In order to unlock the Rat Bond blueprint you must help Mr. Rat by finding a random crawlspace again in Goldmine levels 1-3, you will find him alone with a box. Inside the box is Mrs. Rat, destroy the box to get her out and they will give you the Rat Bond blueprint.
|Version||Additions and Changes|
|0.0.0||Added Mrs. Rat.|
|0.3.0||Mrs. Rat’s crate now heals at a slightly slower rate.|