One.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class One extends Model {
    
    public function getIdAttribute($value) {

        return 'This is an obfuscated id: ' . $value;
    }
    
    // one.id = 5, one.two_id = 3
    
    // $result = App\One::find(5);
    // dd($result)->id; returns "This is an obfuscated id: 5"
}

Two.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Two extends Model {
    
    public function relation() {
      
        return $this->BelongsTo('App\RelatedModel');
    }
    
    // two.id = 3

    // $result = App\Two::find(3)->with('relation'); 
    // dd($result->relation); is null, where an instance of App\One was expected.
}